Amazing Mold Putty and EasyMold are two very commonly available brands of RTV silicone rubber molding putty. What are the differences between these brands and should you choose one brand over the other?
Silicone Rubber Mold Putty is a platinum-cure two-part mold making material that comes in the form of two component putties that you mix together by hand to form a molding putty. You then shape this material over or around an object that you want to copy. The material will then cure to form a durable, flexible mold exactly duplicating the object you shaped it around. Silicone Putty Molds are easy to make, durable, food safe, and you can bake food or polymer clay in them. Read more about Silicone Rubber Molding Material, or read on for my comparison of Amazing Mold Putty vs EasyMold.
I chose to compare Amazing Mold Putty and EasyMold because both brands are readily available in my local craft stores and online. These brands are the ones I see most commonly recommended in online polymer clay forums and groups. In fact, this comparison was prompted by one of these discussions. Someone asked about the best brand. I’d only worked with Amazing Mold Putty and recommended it. Katie Oskin, of Kater’s Acres, recommended EasyMold. We both liked our brands, because they worked, but neither of us had used the other brand and so we really couldn’t comment on the differences. So I bought a fresh box of each and put them through their paces, side by side. Hey, Katie…now we know!!
Description of Amazing Mold Putty and Easy Mold
Amazing Mold Putty
Manufactured by the Alumilite Corporation, Amazing Mold Putty comes in a box containing two containers of putty, each weighing 1/3 lb (150 g). Container A holds a white putty and container B holds a yellow putty. A short instruction sheet is included, written in English. The instructions are simple. Just mix equal amounts of Putty A and Putty B by hand until there are no color swirls remaining. This should take less than a minute. Then shape the putty around the item to be copied, making sure to take less than two minutes. The open time (workability time) is a total of three minutes and the demold (remove the mold from the object) time is 20-25 minutes. Both times can be increased somewhat by lowering the temperature or decreased by increasing the temperature. Molds made with Amazing Mold Putty can be baked at temperatures up to 395°F (200°C).
EasyMold is branded as being by Castin’Craft, but a look on the box and website reveals that it’s actually made by Environmental Technologies, Inc., which may be familiar to you if you work with epoxy resin. (As an aside, many manufacturers of silicone molding material also make casting resins.) EasyMold comes in kits of 1/2 lb and 1 lb (227 and 454 g). Just like Amazing Mold Putty, EasyMold comes in a box with two containers, holding the A and B components of the molding putty. EasyMold’s Component A is white and B is a lovely dark purple. The instruction sheet is quite comprehensive and gives lots of good information in English, Spanish, and French. Just as with Amazing Mold Putty, the open time is three minutes, the demolding time is about 25 minutes, and the molding process is identical. The bake-safe temperature for EasyMold is just a smidge higher at 400°F (204°C).
Amazing Mold Putty vs EasyMold : What are the Differences?
Both Amazing Mold Putty and EasyMold are used in exactly the same way. I found no difference whatsoever in how they mix together and are used to mold an object. Both are easy to mix in your hands and leave a slight oily residue on your fingers. According to the ingredients listed in the Material Safety Data Sheets for Amazing Mold Putty, this is most likely mineral oil. (The MSDS for EasyMold lists only Crystalline Silica (quartz) as a component, which is a bit, um, incomplete. They cite that it’s a proprietary formula.)
The tall, thin containers of the Amazing Mold Putty are a bit harder to get material out of than EasyMold’s containers.
Unlike mixing other two part formulations that you might have used, such as epoxy resin, the mixing ratio for both brands of silicone mold putty doesn’t have to be exact. You do not need to use a scale or measuring spoon. Just make equal sized balls and you’ll be fine.
After curing, I found that both putties created an excellent mold which faithfully reproduced fine detail. EasyMold does create a mold that is stiffer and less stretchy than Amazing Mold Putty. I made a sheet of each putty by rolling them on my pasta machine’s thickest setting. Amazing Mold Putty was quite stretchy, but it really took quite a bit of strength to stretch the EasyMold very far. When I tried to tear each sheet, I could not tear the Easy Mold with my hands but the Amazing Mold Putty snapped in two after a couple of tries.
The instructions for EasyMold warn that there are substances which can interfere with curing (such as sulfur, tin, and stearate). But the instruction sheet for Amazing Mold Putty didn’t mention it. However, I found that this is a known factor for all platinum-cure RTV silicone rubber mold putty and it is, indeed, mentioned in the FAQ on their website. Note, this may be an issue for you when molding rubber stamps as some have sulfur in them. **NOTE: I found that silicone mold putty cure is inhibited by some brands of polymer clay, both raw and baked.
Both mold putties can be used to repair or add to an existing mold to repair a crack or tear. New putty will stick to old putty. This is handy if you want to reinforce a thin area in a mold.
Both brands of mold putty claim that they can be used with chocolate, food, wax, soap, polymer clay, ice, and even resin. Both brands are non-toxic and certified to be safe for use with food. But once used with food, don’t put other things in the mold. Amazing Mold Putty suggests on the box that the molds are perfect for use with their company’s Amazing Casting Resin, which is white, by the way. Keep this in mind…there’s a reason. The instructions for EasyMold say that you can use it with both EasyCast and EnviroTex Lite epoxy resins as long as your mold is older than 24 hours. My experience was a little different, however.
Performance with Resin
Both Amazing Mold Putty and EasyMold easily molded and released the EasyCraft and Envirotex Lite epoxy resins that I used. But there’s more to a good cast than a good shape, as I found out. The instructions for EasyMold clearly state that the cured putty is usable for general molding but needs to cure for at least 24 hours or be heat cured by baking at 350°F (177°C) for 30 minutes before being used with resin. This is because gases are released as the putty fully cures. The instructions for Amazing Mold Putty don’t mention this.
I had to check it out. And sure enough, freshly cured silicone mold putty produces resin casts with a very bubbly surface. It was quite pronounced with EasyMold, but it was definitely a factor with fresh Amazing Mold Putty molds as well. I tried again with heat cured molds. And while the amount of bubbles was reduced, the casts were still quite bubbly. With a mold that was 48 hours old, there were still noticeable bubbles being produced in the EasyMold mold, creating a pitted resin surface. I used both EasyCast and Envirotex Lite epoxy resins, by the way, and had similar results.
Amazing Mold Putty behaved very differently with resin. Amazing Mold Putty molds didn’t have pronounced bubble issues once the molds were older than 24 hours. But they aren’t really usable with clear epoxy resins like EasyCast and Envirotex Lite, either. That’s because the resin cast comes out with a very finely pitted surface giving a frosted look on the surface of the resin. It feels smooth, but it’s not. Again, this is not mentioned in the instructions for Amazing Mold Putty, but the video of the product’s use does mention it. Now we know why they suggest using it with their white colored Amazing Casting Resin! It does work with epoxy resin, you just won’t get a clear surface.
And there’s one more odd thing about using resin with EasyMold. I knew I hadn’t spilled the resin when I poured it. But after 12 hours, the outside of the mold was sticky. I got out my fancy reading glasses so I could see up close and found that the purple EasyMold “sweated” an oily substance while the resin inside of it cured. Amazing Mold Putty did not do this. I thought it was a side effect of the mold curing, but this didn’t happen when I tested freshly mixed EasyMold and left it overnight. The mold with resin it it got “sweaty” and the mold without resin in it didn’t. Odd. Two day old molds did not sweat like this when I used resin.
That’s kind of a long winded way of saying that you can’t use clear resin with Amazing Mold Putty because the surface will be frosted. And EasyMold needs to be well cured if you’re going to use it with epoxy resin or you will get bubbles and a pitted surface. And if you’re using EasyMold, don’t be shocked to find that it has sweated an oily substance.
As an aside here, Laurel Steven mentioned in a comment that she dislikes using Amazing Mold Putty because the molds would “sweat an oily substance over time”. Hmm. I’m not surprised one bit! But I’ve used Amazing Mold Putty for a while and have molds a year old and so far so good. So if this happens to you, you’re not the only one!
Performance with Polymer Clay
Since I work with polymer clay, my main reason for using RTV silicone rubber mold putty is to create molds and texture sheets to use with polymer clay. This is absolutely a fantastic use for silicone molds!! You can get excellent details and make molds that allow you to reproduce a shape or a motif many times over.
I found no difference between polymer clay impressions created with Amazing Mold Putty vs EasyMold. Both materials produced excellent casts with tremendous detail. Both mold putties are chemically compatible with polymer clay and both brands of mold can be baked with polymer clay inside, both at 275°F (135°C) that Premo requires and yes, even at the 300°F (150°C) that Kato Polyclay requires.
And beyond making molds, you can use RTV silicone rubber mold putty to make texture sheets for polymer clay. Because the mold material doesn’t stick to what it’s being molded upon, you can take impressions of nearly anything! Just mix up the putty, press it onto something with great texture, and let the putty cure. Peel it off after curing and you’ve got a wonderful texture sheet for working with polymer clay. See how Kristi Bowman used silicone mold putty on some cauliflower to make textures that she used with metal clay. How cool is that?
Amazing Mold Putty vs EasyMold, which is better?
Amazing Mold Putty and EasyMold silicone mold putty work very much in the same way and there are not many differences between them, especially if you’re not going to be using your molds to cast resin. I’ve now worked with both and they seem to be quite comparable. You would do well with either brand.
I’d probably pick the purple EasyMold next time, though. Mostly because I prefer the color. And I like that it creates a slightly firmer mold.