Testing 41 Polymer Clay Sealers

No polymer clay group or forum seems to escape the inevitable questions about using polymer clay sealers, varnishes, and glazes. Which ones are “clay safe”? Which ones turn sticky or get cloudy or peel off? Why are there so many opinions? Do you even need to use a sealer at all? (No, you don’t.) There are so many questions and no solid answers. But really, unless you test these products, it’s impossible to know which are the best polymer clay sealers. So that’s exactly what I did. (By the way, I’m using the terms sealer and varnish interchangeably…I found no difference.)

Over the past two years, I have gathered all the polymer clay sealers, varnishes, glazes, and dimensional glazes that I could find. I even brought some varnishes from the UK, so I could find a Varathane alternative for British clayers. I applied these products to five different brands of polymer clay and evaluated their performance over five months. The results are not what I had expected. Frankly, most varnishes failed on at least one brand of clay, and there was only a small handful that performed well on all five brands of clay. Varathane still scores well, but some of the others I’ve recommended in the past, do not. (Yes, I have now changed those articles!)

Summary of Sealer Tests

  1. For full results on all sealers, check my spreadsheet here.
  2. Each polymer clay sealer behaves differently on different brands of clay. The same varnish would be great on one brand of clay and fail miserably on another. Choose the right polymer clay sealer for your brand of clay.
  3. Nearly all varnishes, glazes, and sealers were unsuitable on at least one brand of clay.
  4. You don’t need to use a sealer in many cases, but if you do use one, choose PYM II, Helmar Crystal Kote MatteVarathane, Pearl Ex Varnish, or Cernit MATTE varnish for maximum compatibility with all clay brands.
  5. You may get better performance by matching the sealer to the brand of clay, and not looking for one that works on all.
  6. Consider using liquid clay when sealing surface treatments on polymer clay.
  7. Skip to read my TOP VARNISH PICKS.
  8. Skip to read the best sealers for each clay brand:
  9. You can also skip to find the best varnishes by gloss level:

Testing Polymer Clay Sealers

This was a big job, and so this article will have a lot of information in it. Grab a cup of something refreshing and settle in for some reading. Based on my spray sealer tests, I knew that different brands of clay would react differently. I chose Sculpey III, Kato Polyclay, Premo, and Fimo Professional. Syndee Holt asked me to test Souffle as well, and I was happy to add it in. I wanted to test for both cloudiness and yellowing, so I needed both black and white clay. I added colored clay as an extra test. Here’s how I set it up.

Test tiles were made from five brands of clay to use as the base for testing polymer clay sealers.
Here are the test tiles that were used to evaluate the polymer clay sealers. Included were Sculpey III, Kato Polyclay, Premo, Fimo Professional, and Souffle.

How Sealers Were Tested

Master Cane

I made a master cane with each brand of clay using black, white, and primary colored clay. These canes were about 4 lbs (1800g) each. You can see how I reduced these canes using square dowels here. I then used my LC Slicer to make slices from each cane. Each slice became a test tile. I baked all tiles at their proper temperatures according to their label directions. Each tile was wiped with alcohol to remove any oils that were on the surface. Finally, the tiles were labeled on the back with a paint marker. Here’s the Kato master cane.

Varnish Application

Each varnish was first stirred with a new wooden stir-stick. I applied three coats to the tile with a soft brush using identical stroke patterns on each tile. The surface was allowed to dry to the touch between coats (typically 30 minutes or so). I did not heat set the tiles by baking them after the varnish dried.

Storage of Tiles

The tiles were stored flat in the open air, on a rack, in my studio for five months. My studio is exposed to normal household temperature conditions with an open studio window at times. Both temperature and humidity changed greatly as the season changed from summer through autumn into winter. They were evaluated at 1 week, 1 month, and five months.

Brush strokes are a problem with many polymer clay sealers.
Here’s an example of brush strokes on a tile made from Fimo Professional. The tile on the left is bare, the tile on the right has three coats with Sculpey Satin Glaze.
This spray varnish didn't spray evenly and was easily scratched from Souffle polymer clay.
Molotow Spray Varnish didn’t spray evenly on this Souffle tile, and it was easily scratched off.
Some polymer clay sealers get sticky with time.
This Premo tile was coated with Krylon Preserve It!, a sealer intended to protect artwork. As you can see, it was so sticky that the police could use this to take people’s fingerprints!
Many polymer clay sealers contract or shrink over time, causing the clay itself to curl.
Many polymer clay sealers shrink or contract over time, causing thin pieces of polymer clay to curl.

Evaluation of Sealers

I evaluated the sealer itself for color, clarity, thickness, odor, and drying speed. These features are the same for all clays as they refer to the sealer itself. I evaluated the test tiles (the dried varnish) for gloss level, smoothness, cracking, clouding, yellowing, scratch resistance, peeling, stickiness, and thickness of coating (coverage).

I tested the scratch resistance by using my fingernail to dig at the coating, and to see if it would peel once scratched. By pressing my finger onto the tile and lifting, I tested stickiness. If the tile stuck to my finger at all, it gained a “sticky” rating. I also evaluated the tiles for the “feel” of the varnish and for smoothness issues such as brush strokes or bubbles.

Criteria for a Recommendation

As you can imagine, there was a lot of judgment involved here. I tried to be objective, but how do you really quantify “how much” scratching or how much cloudiness is too much? I would still give a “yes” vote for a sealer with poor performance in one area if it was really good in all the others.

However, if there was any stickiness at all, at any point during the testing period (after the initial drying time), the varnish would receive a “no” vote, even if the tile wasn’t sticky later. I also gave a “no” vote to any sealer that could be easily scratched off with little effort. To get my top pick as “the best,” the product had to work well on all five brands of clay that I tested.

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Sealer Results

For detailed results of my polymer clay sealer tests, have a look at this spreadsheet. There you can see exactly how each sealer scored, on each characteristic, on each brand of clay. I would like to give you a yes/no for each product, but because they acted so differently on the various brands of clay, I can’t do that. Here is a summary of how each product performed.

SpraysI tested more spray coatings on polymer clay, once again PYM II was the only one that worked well.

  • Krylon Preserve-It! Spray – This spray never dried and was extremely sticky and goopy on all brands.
  • Krylon Workable Fixatif Spray –  This spray was very pebbly and did not spray evenly on the surface. Sticky on Premo, Fimo Pro, and Souffle.
  • Molotow Premium Spray – While this spray was only sticky on Fimo Professional, it didn’t spray evenly to make a smooth surface. It was very pebbly.
  • PYM II – As with all my other tests of this spray, it worked beautifully on all brands of clay.
  • Helmar Crystal Kote – The gloss version works nicely on all brands but Fimo Professional. The matte version, which I highly recommend, is invisible on your project and has a matte finish. Read more about Helmar Crystal Kote here.

For more spray sealer tests, check out my article that is specifically on that subject.

Matte VarnishesThese matte polymer clay sealers were tested for performance on five brands of polymer clay.

  • Cernit Matte Transparent Varnish – One of the very few varnishes that are scratch-resistant on Kato. Makes a lovely dry-feeling and durable varnish on all clay brands tested but is not really very matte. It’s more of a satin.
  • Swellegant Clear Sealant – Sold by Christi Friesen, this light-bodied sealer is perfect for fixing surface treatments. Sadly, it beads up on Kato, but is nice on the other clay brands.
  • DuraClear Ultra Matte – Very light-bodied dead matte varnish that is scratch resistant on Fimo Pro and Souffle and good for low-wear items made from Sculpey III and Premo. Not suitable for Kato as it can be very easily scratched and peeled off. My new favorite matte varnish!
  • Golden Matte Polymer Varnish with UVLS – A dead matte varnish that is highly recommended in the polymer community. However, it scratches very easily from Sculpey III, Kato, and Premo. It gets sticky on Fimo Professional. It works better on Souffle, but can still be scratched off.
  • Duncan Matte Sealer – Sold by ceramic suppliers, this sealer is sticky on Premo, Fimo Professional, and Souffle and scratches easily from Sculpey III and Kato.
  • Mod Podge Matte – Similar to white glue, this paper crafting stand-by has terrible brush strokes and isn’t very matte. It turns white when in contact with water. There are better choices.
  • Daler-Rowney Soluble Varnish, Matte – Used for varnishing acrylic and oil paintings, I just added this in because I had it on hand. It doesn’t work on any brand of clay that I tried. Sticky and gooey.
  • Liquitex Matte Varnish (red label) – Also used to varnish paintings, this one peels easily from all clays that I tried, and was sticky on Premo, Fimo Professional, and Souffle.
  • Genesis Heat Set Matte Varnish – Not so much a varnish as a version of liquid clay, this mayonnaise-textured gel works great on all brands of clay, chemically. But the texture of your application method will show, whether you sponge or brush. It does not self-level. (NOTE: Sadly, the entire line of Genesis products is no longer being manufactured. I’ve left this info in place for archival reference.)

Satin or Semi-Gloss VarnishesSatin or semi-gloss polymer clay sealers were tested.

  • Final Coat – Available in low gloss and semi-gloss, this light-bodied sealer works nicely as a fixative for mica powders. Not a heavy-duty protectant, but works nicely on all clays except for Kato which either beads up or scratches readily.
  • Liquitex Satin Varnish (red label) – Cloudiness is apparent on dark colors. Peels easily from all clay and gets sticky on Premo and Fimo Pro.
  • Sculpey Satin Glaze – Has obvious brush strokes (esp Fimo Pro) and is cloudy on all clays. Scratch-resistant on Kato (which is unusual) and Souffle.
  • Polycrylic Clear Satin – This wood varnish has a vinyl-like or rubbery feel to it, but works nicely on Sculpey III, Fimo Pro, and Souffle. Scratches very easily from Kato and Premo.
  • Varathane Polyurethane Satin – Also a wood varnish, this polymer clay favorite has a dry feel and no stickiness on any brand of clay. Can be scratched off if you dig at it on all brands but Fimo Pro.
  • Future Acrylic Floor Finish – No longer available (replaced by Pledge Floor Care), this light-bodied and completely clear finish is lovely on all brands of clay. Not a true gloss, more of a semi-gloss, but can be glossier with many coats. Smells like apples and pears. Is never sticky. Sadly, this can be scratched off most clays and isn’t terribly durable.
  • Pledge Floor Care Finish – Nearly identical to Future (above) except that it has a different smell and is just a smidge more glossy. Does not get white when in contact with water.

Gloss VarnishesThese gloss polymer clay sealers were tested on five polymer clays. Results at The Blue Bottle Tree.

  • Golden Polymer Varnish w/UVLS – This popular varnish peels easily from all clays, beads up on Kato, Fimo, and Souffle, and is sticky on Fimo Professional. I know it’s popular, but it really scored badly here.
  • Media Gloss Varnish – I found this in HobbyCraft in the UK, but it is available in the US as well. It beads up on Kato, Premo, and Fimo Pro, and scratches easily on all but Souffle. On Souffle, however, it is a phenomenal varnish giving a durable high gloss shine. Highly recommended for Souffle only!
  • Cernit Transparent Varnish, Glossy – Beads up on all clays, but it’s so bad on Kato that you cannot get any coverage at all. Cloudy on Kato and Souffle.
  • Duncan Gloss Sealer – Here’s another ceramic sealer that had terrible brush strokes and was sticky on all brands of clay.
  • Sculpey Gloss Glaze – There were obvious brush strokes and distinct cloudiness on all brands of clay. Oddly, I found that by 5 months, this finish crackled on all brands of clay, and was most obvious on Kato.
  • DuraClear Gloss Varnish – This craft store varnish beads up on all brands of clay, but eventually smooths out with several coats. Can be easily scratched off Kato. Has a nice feel on Fimo, but caused the test tile to curl. On Souffle it seemed great until I noticed that it had fine bubbles in the varnish. Few things are good on Fimo, so this is a good one to try.
  • Gloss Medium & Varnish (green label) – This was sticky on all clays tested. Do not use.
  • Liquitex Goss Varnish (red label) – Cloudy on Sculpey III, Premo, and Souffle. Sticky on Fimo. Fine bubbles on Souffle. Beaded up on application on all clays. There are better varnishes.
  • Fimo Gloss Varnish – Beading up and cloudiness are the issues with this varnish. Makes a good varnish for Fimo Professional and Souffle, however.
  • Ronseal Interior Gloss Varnish – This is a UK brand of hardware store polyurethane and it’s truly remarkable and scratch resistant on Sculpey III, Kato, and Premo. But it is sticky on Fimo Pro and Souffle. (Some have noted it can also be sticky on Premo, so always test!)
  • Wilko Quick Dry Varnish – Another UK varnish, this is lovely on Sculpey III, Premo, and Souffle. It peels from Kato and is sticky on Fimo Professional.
  • Polycrylic Clear Gloss – Available everywhere in the US, this varnish has a vinyl-like feel and isn’t very gloss on any clay. Gives a good finish on all but Kato. It’s satin on Fimo Pro, however, but glossier on Souffle.
  • Varathane Polyurethane Gloss -This much-loved polymer clay sealer is dry and lovely on all brands of clay. It can scratch and peel off if you dig at it, but it’s perfectly durable for all but the most roughly-handled pieces.
  • Mod Podge Gloss-Lustre – This paper crafting glue-based decoupage medium is very glossy but gives terrible brush strokes. Not at all water-resistant, this turns brilliant white when it gets wet. Not really a suitable polymer clay sealer or varnish.
  • Darwi Vernis – This alcohol-based varnish from the makers of Cernit gives a lovely thick, glossy coating. But it scratches easily from Kato. It turns white and crackles if flexed, so don’t use it on anything flexible (like thin cutter earrings). But this is a great coating on beads or anything that needs to be hard and shiny.
  • Pearl Ex Varnish – There is no mica powder in this, but it is sold by the same company. This satin-sheened varnish has a lovely dry feel and is scratch resistant on all clays. It leaves a slight orange-peel texture on Fimo, but is wonderful on the other brands of clay.

Dimensional GlazesThese dimensional glazes were tested on five brands of polymer clay.

  • Aleene’s Jewelry Pendant Gel – A very glossy dimensional glaze that does show scratches and can peel if you pick at it. Nice and smooth on most clays, but is sticky on Fimo Professional.
  • Mod Podge Dimensional Magic – Obvious brush strokes and bubbles make smooth application impossible. Sticky on Premo. Shrinks over time, causing the clay to curl upward. (And this one fared pretty badly on paper in other (unpublished) tests, too.)
  • Diamond Glaze – Dries blotchy with brush strokes and bubbles. Gets sticky on Sculpey III, Premo, and Fimo Pro. Shrinks and causes the clay to curl.
  • Triple Thick – Readers tell me this glaze turns sticky, but I didn’t see it on any brand of clay (so far). All tiles showed blotchy brush strokes. This is the glossiest of all the products I tested. All tiles curled upward. Has a rubbery feel that shows fingerprints, that are highly visible on black.

Best Sealer by Clay Brand

Because there is so much information here, I’ve struggled to present it in a way that makes sense for you. The above info is great if you want to see how a specific polymer clay sealer works, but it’s pretty hard to figure out the best sealer for the brand of clay that you use. To help clarify, here’s a list of products that worked well with each brand of clay. I’ve highlighted my top pick for each clay brand in green (though this is subjective and you might like a different product better).

Sculpey III

These polymer clay sealers tested well on Sculpey III.
These polymer clay sealers and varnishes performed well on Sculpey III.
  • PYM II
  • Sculpey Satin Glaze
  • Polycrylic Clear (satin and gloss)
  • Varathane (satin and gloss)
  • Final Coat (both semi-gloss and low-gloss)
  • Cernit Matte Varnish
  • Swellegant Sealant
  • DuraClear Ultra Matte Varnish
  • Ronseal Interior Gloss Varnish
  • Wilko Quick Dry Varnish
  • Pearl Ex Varnish
  • Genesis Heat Set Matte Varnish (no longer available)
  • Helmar Crystal Kote Matte

Kato Polyclay

These sealers performed well on Kato Polyclay.
These polymer clay sealers and varnishes performed well on Kato Polyclay. Note how there are fewer, and they tend to be different to those that work with the other clay brands.
  • PYM II
  • Sculpey Satin Glaze
  • Varathane (satin and gloss)
  • Cernit Matte Varnish
  • Ronseal Interior Gloss Varnish (UK only)
  • Pearl Ex Varnish
  • Helmar Crystal Kote Matte
  • Aleene’s Jewelry Pendant Gel
  • Genesis Heat Set Matte Varnish (no longer available)


Polymer clay sealers tested well on Premo polymer clay.
These polymer clay sealers and varnishes performed well on Premo.
  • PYM II
  • Polycrylic (satin and gloss)
  • Varathane (satin)
  • Final Coat (semi-gloss and low-gloss)
  • Cernit Varnish (matte and gloss)
  • Swellegant
  • DuraClear Ultra Matte Varnish
  • Ronseal Interior Gloss Varnish (UK only)
  • Wilko Quick Dry Varnish
  • Pearl Ex Varnish
  • Aleene’s Jewelry Pendant Gel
  • Genesis Heat Set Matte Varnish (no longer available)
  • Helmar Crystal Kote Matte

Fimo Professional

These polymer clay sealers and varnishes performed well on Fimo Professional in my tests. Read more at The Blue Bottle Tree.
These polymer clay sealers and varnishes performed well on Fimo Professional.
  • PYM II
  • Polycrylic (satin and gloss)
  • Varathane (satin and gloss)
  • Final Coat (semi-gloss and low-gloss)
  • Cernit Varnish (matte and gloss)
  • DuraClear Ultra Matte (and gloss)
  • Fimo Gloss
  • Pearl Ex Varnish
  • Genesis Heat Set Matte Varnish (no longer available)
  • Helmar Crystal Kote Matte


These varnishes and polymer clay sealers tested well on Souffle.
These polymer clay sealers and varnishes performed well on Souffle.
  • PYM II
  • Sculpey Satin Glaze
  • Polycrylic (satin and gloss)
  • Varathane (satin and gloss)
  • Final Coat (semi-gloss and low-gloss)
  • Cernit Varnish (matte and gloss)
  • Swellegant
  • DuraClear Ultra Matte
  • Golden Polymer Varnish with UVLS (matte)
  • Media Gloss Varnish
  • Fimo Gloss
  • Wilko Quick Dry Varnish
  • Pearl Ex Varnish
  • Aleene’s Jewelry Pendant Gel
  • Genesis Heat Set Matte Varnish (no longer available)
  • Helmar Crystal Kote Matte

Um…I had different results!!!

Did your favorite coating receive a poor score? Have you had bad results with a polymer clay sealer that I’ve recommended? This is not surprising. Varnishes, sealers, and polymer clay formulas are constantly being tweaked by the manufacturers. I can only vouch for the clay that I have and the bottles and jars of product that I tested. There are SO many variables and even things such as contamination by brushes can change the results. Even a different manufacturing lot can perform differently. Undercured polymer clay can also result in sticky paints, sealers, and varnishes. Make sure you’re baking your clay properly.

Because of this variability, you should always test any polymer clay sealers and varnishes that you use with your clay. This is even true if you’ve successfully used a polymer clay sealer with a different brand of clay, and especially relevant when working on an important project.

Another factor that comes into play is paints. When you apply a varnish over a paint, the potential increases for chemical interactions. Many paints remain sticky on polymer clay, too, and adding a varnish over that can give highly unpredictable results.

Phyllis Cahill ran a series of tests evaluating how well sealers adhered to various brands of clay and surface treatments such as metal leaf and Perfect Pearls. Her results differed from mine to a degree, which underscores the variability we seem to get when working with polymer clay sealers and varnishes.

Tip: If you have a piece that’s sticky from incompatible paints or polymer clay sealers, you can often cover the stickiness by giving it a coat of Varathane.

Recommendation for Polymer Clay Sealers

So bottom line, what is my top pick for which sealer I recommend? It’s really hard to say because it depends on what effect you want. Few of these sealers are identical. Some are thick and glossy, some are thin and matte. There are no quick and easy answers. Here are some key points.

  • Varathane is an excellent all-purpose varnish that shows no signs of being sticky on any brand of clay. If you use many brands of clay and only want to invest in one polymer clay sealer, this is probably the best bet. It is not, however, the best-performing varnish on any one brand.
  • Pearl Ex Varnish performed well on all brands of clay, a bit less so on Fimo Pro. Certainly a good varnish to use.
  • Cernit Matte Varnish is another stand-out, but it’s not very matte. It’s more like a satin.
  • DuraClear Ultra Matte Varnish by Americana gives a luscious dead matte finish on all clays except for Kato.
  • Final Coat and Swellegant are both super light bodied sealers that are a great alternative to PYM II when you need to seal mica powders. They go on quickly without much brushing and dry in no time.
  • Varathane is now available in the UK from Amazon. But if you go to Homebase, you can get Ronseal Interior Gloss Varnish that performs beautifully on all but Fimo and Souffle.

Changing Recommendations

Don’t ever say I won’t admit when I’m wrong. Sadly, I have given bad advice in the past! Previously, I’ve recommended Golden Polymer Varnish and Liquitex Varnish. I did use both varnishes in practice, and they did work for me. But that was before I tried those varnishes on multiple clay brands. Because these products performed poorly in these tests, I no longer recommend them and have changed the relevant articles. My apologies if I led you astray. I was going on the information that I had at the time. I know more now. 🙂

Also, ALWAYS ALWAYS ALWAYS test the particular bottle of varnish you have with the brand of clay you’ll be using. Manufacturers change formulas, and there are different formulas in different regions due to supply issues and local laws. Always test to be sure!

Polymer Clay Sealers – Only If you Have To!

As you, hopefully, can see, there is no one sealer or varnish that works beautifully and perfectly in all situations and on all brands of clay. It’s important to note, polymer clay sealers add an element of complexity and bring in the chance for brush strokes, peeling, stickiness, and cloudiness. Please know that polymer clay does not need to be sealed. It’s a durable plastic (vinyl) and the only thing that needs to be sealed is surface treatments that you put ON the clay.

You can use polymer clay sealers and varnishes to change the gloss level of your work, but if what you’re looking for is a super smooth and glass-like finish, the smoothest and most durable solution is to sand and buff your clay. Not sure how to do that? I wrote a 120 page eBook that covers this very subject, in-depth! Click here to learn more about the Sanding and Buffing (and Finishing) eBook!

Alternatives to using Polymer Clay Sealers?

As I just said, the best way to get a smooth, glass-like finish is to sand and buff your project. Knowing how to do this quickly and easily (and without painful fingertips) is a valuable skill to add to your repertoire. Get the 120 page eBook here!

Another solution is to use liquid polymer clay as a clear coat and fixative. Translucent Liquid Sculpey makes an excellent matte fixative. Just use a cosmetic sponge to (very) lightly dab it onto the surface of your project, then bake again. Yes, this can be done over paint and other surface treatments.

Liquid Kato Polyclay can be used to make a super-smooth and glossy finish and sealer on your clay projects. There is a bit of a learning curve, but when done using a heat gun, liquid Kato makes a hard, non-rubbery, durable, and chemically compatible finish on your clay. To learn more about that, I highly recommend getting Debbie Crothers’ video tutorial Curing Liquid Kato Clay. She takes away all the mystery of learning this essential skill.

Alternatively, resin (both epoxy resin and UV resin) is also a good method for coating polymer clay. But I didn’t test resins in this article…that’s for another day.


In conclusion, there are some people I want to thank. Although I did buy most of the clay and sealers used in this article, I was thrilled to receive some of the products to help me with the cost a bit. Many thanks to the following people:

Sculpey sent me a huge package of Souffle in just the colors I needed to make the 4 lb cane I used for the Souffle test tiles.

Bottles of Final Coat were provided by Wendy Orlowski of Shades of Clay. This was one of the first sealers I collected, so it’s been a while. Thank you for your patience, Wendy! Shades of Clay is a great Canadian polymer clay resource!

Cernit Varnishes, both Matte and Gloss, were provided by Marina Taenkova of Marka Decor.

I wanted to include Christi Friesen’s Swellegant sealant in these tests, and she happily sent me some to test.

And if sealers aren’t your thing, learn more about the art of sanding and buffing…

Sand better, not harder

Everyone loves a perfectly smooth, glassy finish, but it seems to be elusive. Does your polymer clay look scratched and rough after sanding? This course will change everything.

129 thoughts on “Testing 41 Polymer Clay Sealers”

  1. Hi Ginger, Thanks so much for all your hard work. Sooo I have been using Liquitex Matte (Red Label) off and on when needed. But, now that I see you have updated your recommendations I am wondering. How long did it take for you to notice stickiness on Premo clay? I am worried I need to go back and try to fix what ever stock I have left and put out a disclaimer that I will fix any items that have issues. I haven’t noticed any stickiness myself but pieces only tend to sit on the work bench for about a week before I package them up. Thanks again for all your help!

  2. I love your website for info on polymer clay, BUT, I have a HUGE major project that’s going to be a permanent outdoor instillation, and there’s a void in the information provided on your website as it applies to my project.
    I’m making several fairy houses, using a balsa wood form, and the fairly new polymer clay brand CosClay.
    I used mica, chalk pastels, and cheap acrylic paint for details before baking, and now I’m worried about having to seal it to protect it from our Ohio weather. These aren’t small, either. I’m working on a 1:24 scale.
    I NEED to seal the inside wood to protect it from moisture, but the outside I wasn’t planning on sealing until I read about mica and the like wearing off.

    I’d need a matte, ideally a spray, for the outside, JUST to protect the powders and paint from wearing off, and a gloss one for small, metallic details.
    I was thinking of coating the inside in something like FlexSeal for the inside, and there ARE windows, so that needs to be polymer clay contact safe, too.

    The amazing thing about CosClay is that it’s FLEXIBLE, like, REALLY flexible after baking. Now, I don’t have any wild details to worry about, but this is for a public space, so I wanted them to be durable.

    Does anyone know anything on if I need to seal these pieces, and if so, what I can use safely? The information just isn’t out there, since CosClay is so new

    1. Several thoughts. 1. Cosclay is just polymer clay. I haven’t tried specific sealer with it, but there’s no reason for it to be any more difficult than other clays.
      2. Weather in Ohio is going to be harsh. Freeze/thaw is going to be your biggest enemy. A varnish (which just sits on top of the clay) isn’t going to help that. (Varnish helps wood because it goes down into the fibers. Polymer clay won’t have this advantage.) I think the fundamental idea of polymer clay over wood in this environment is more of an issue than coating the mica powder on the surface of the clay.
      3. Varnish will eventually wear off due to cracking.
      4. Outdoor in this climate, mildew and grime is going to be an issue.
      5. Since Cosclay is so flexible, I’m not sure it will be durable where it’s bonded to rigid areas.

      It sounds like you need some trial runs. Make some samples and give them some shower/sun time to see what types of damage you really need to be working to prevent. Good luck!

  3. Pingback: Which Sealer Is The Best – Testing Polymer Clay Sealers – Polymer Clay

  4. I use a lot of color shifting Mica’s in my “mermaid style” earrings and pendants. What kind of soft brush do you recommend for the varathane ?

  5. How did you make that rainbow cane? I love it I’ve bought a few of your tutorials but so far they are the basic ones

  6. I think I have read this five times and learn something new every time. I primarily use Souffle or Primo and I have had pretty good success with MinWax Polycryptic except sometimes a couple of the earrings will stick to one another. They don’t feel sticky to the touch and they come apart with no damage but I would like to eliminate that if possible. I’m going to try the “rebake” to see if that helps. (I have test chips) I also bought some Varathane. I like it but it does this weird wrinkle thing. That is the only way I can describe it. Most of the piece will look great and then there will be this wrinkle that looks like a river on a topography map in one area. It happened on every piece I did. Do you think it could be caused by applying too much? I use the drop and toothpick method to spread the Varathane. Thank you for any insight and I will keep playing.

  7. I have been starting up with coasters recently and going for both the look of wood, (which I achieved by pressing various random pieces of wood and Popsicles sticks into the clay for texture then removing them) and a glossy look. I have only ever used Sculpey III, baked according to instructions. I found that when I tested out the plain clay it started scratching right away. I wish I had read this before trying Sculpey Gloss glaze hoping that would protect it. That scratches too. Is there a way to protect it better now that the glaze is already on it or is it too late?

  8. Melody Hope Stein

    In the early days, I used Pledge Future acrylic coating with great success. What do you think of that?

  9. Pingback: ¿Es necesario barnizar la arcilla polimérica? Te lo cuento aquí.

  10. Such great information thank you! I wondered if you had any suggestions for the best varnish to use on coasters? I’ve made some recently and particularly on black clay (I’m using fimo) I’m finding they’re getting faint white ring marks when used for a little while. I’ve seen Varathane suggested in a fee places but I can’t seem to pick it up in the UK. Would another polyurethane work, for example, I can find some Ronseal polyurethane quite easily? Any suggestions would be much appreciated 🙂

    1. I’m not Ginger – obviously 🙂 but if my polymer clay piece is going to get a lot of use, and possibly get wet, ie: coasters, I’d not seal them. Unless you have applied something that has to be sealed, sand and buff – it’ll give you the most beautiful finish.
      If however you embellished with paints, powders etc, epoxy resin is what I’d use. Hope this helps a bit!

      1. Hi Ginger, would you recommend the same products to protect a piece from incompatible products? For example: Bake and seal with one of the matte finishes you recommend, leave to dry and cure for approximately 2 weeks depending on the weather, then add a solvent based paint, like Freida glass or Pebeo Fantasy?
        I’ve done this to other incompatible medias but not pc.
        Thank you!

  11. Can you tell me what you think “inklings by Papel Giftware” figures are covered with? They almost feel rubber or wax like. It’s hard enough that I can’t put a thumb nail in it but so soft and smooth to the touch. I have the figure “Daisy Mae” and even the bow in her hair is a little flexible!

    1. I’ve never seen these figures personally. I did google the name and found some images. It appears that they’re made of polymer clay. I don’t believe they’re covered with anything. That’s just what polymer clay feels like.

  12. Nathalie Parfait

    Did you know there is a Kato Polyclay Supergloss Varnish ? Perhaps it is better suited for Kato polymer clay? I’ve never seen it here in Europe. Thank you for the test and this excellent review.

  13. Hi, do you know if permanent acrylic varnish (like Vallejo Matte Permanent Acrylic Varnish) is good over acrylic paint on air dry clay? Also, do you know anything about the toxicity of acrylic varnish versus polyurethane varnish?
    Any thoughts on Vallejo brand varnishes in general?
    Really appreciate the in depth reviews!!!

    1. I’ve not encountered that brand before. There is a huge overlap between acrylic and polyurethane products. They’re not mutually exclusive. In other words, some varnishes contain acrylic, some polyurethane, some both. The best place for safety info is the individual manufacturer because they have access to their testing data. Most companies make it a bit complicated to get the info.

  14. Hi, Ginger. I have been using Duraclear Gloss over some pieces I painted with acrylic and now (after about two years) I have a piece that looks kinda like it has yellowed. I just wondered if you had had this experience. I’m hoping to sell some eventually and haven’t had a problem with this varnish except this piece, but now I’m worried!
    P.S: your site is very helpful

    1. I haven’t used Duraclear Gloss, so I can’t say. Generally, water-based varnishes don’t yellow much. Plus, there could be other things going on, too. Resin, on the other hand, usually yellows quite readily.

  15. Peta Diane Young

    Hello Ginger and thank you very much for all the wonderful work you do with your testings etc, can you please recommend which sealers to use from Australia, we don’t have the same brands as you over here, kind regards Peta

    1. Well, I don’t know what sealers you have in Australia and I wouldn’t be able to buy them unless they were also here in the US. I did the best I could. DuraClear is available worldwide, so is Sculpey Glaze. Swellegant sealer. In fact, most of the names listed are available in other countries. Try going to 2Wards Polymer Clay to see what clearcoats they sell and compare that against the ones I listed. Hope that helps!

  16. Hey Ginger!
    Any info about varnish/sealants used with Pardo clay?

  17. deborah deforge

    Hello, just found your wonderful site today. So much great information. I was looking for information on adhering polymer clay to wood, after the fact. I took thin, spaghetti like stands of clay and made designs with them on a small flat piece of wood. After cooking I was pleased that the clay strands adhered to the wood. But now that I want to display this piece on a wall I am afraid over time the thin stands will become loose, so now I am looking for a way to better adhere them to the wood panel.
    I am now thinking of using liquid Poly, hoping it will seep through a bit and adhere both to the wood and to the other strains of clay.
    Your thoughts?

  18. Does the scupley satin glaze work for protecting acrylic paintings on polymer clay. I’m trying to figure out a good way to seal it in so it doesn’t scratch and peal off and am seeing others who paint on top of poly clay do everything from not sealing it to getting an entire resin set-ups to seal their paintings. Any help would be greatly appreciated! 🙂

    1. It depends on how well your paint attached to your clay and also what effect you want. It’s always best to have a paint that attaches well to the brand of clay that you’re using. Adding clearcoats over paint can often be problematic and add an extra complication that sometimes doesn’t go well.

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