According to the Interwebs, I am the only person on Earth who cannot get beautiful bubble free castings using Little Windows casting resin.
Painting the eyes was my favorite part of making my first furry mask. I had fantasies of a little sideline on Etsy painting eyes. In order to keep the price competitive with what other sellers on Etsy were offering, I'd need to find a way to cast the eyes myself. I figured the eyes would cost me about $10 a pair to make using Little Windows resin, where they cost me $30 ready made from Dreamvision Creations on Etsy. That, plus the fact Little Windows resin is supposed to be non-toxic and odorless, made this option initially very attractive.
I saw some very cool eyeball painting techniques on the Little Windows website and wasted a lot of time trying them out. (Here they are, they really are beautiful!) Specifically, they involved making the castings in layers-one for the pupil, one for the iris, and one for the eyewhites (if desired) and painting each one after it set, embedding the paint and achieving perfectly circular and concentric areas of color, in theory anyway. Firstly I found that the resin would almost always crawl up the side of the mold I was pouring it on, making that area somewhat less than perfectly circular (and trying to brush it away would only change its shape to be a different kind of less than perfectly circular, and probably introduce lint besides) and secondly I found that I would not get the desired follow-me effect using this technique. The color had to be entirely on the back of the casting for that to work. (I did, however, come up with some eyeballs that made some very cool props for family photos, as you can see.)
First mistake: not getting part A warm enough, so that the mix would be too thick for any bubbles formed while stirring to rise up and pop. If Part A was too cold, bubbles were also more likely to form while stirring in the first place.
Second mistake: getting part A too warm. The mix would be beautifully bubble free in the mixing cup, but new bubbles would form no matter how gently I poured down one side of the mold and then the mix would set too fast to allow these bubbles to rise up to the top and pop.
Third mistake: mixing the part A and part B as little as possible, so that there would be no bubbles but there would also be unmixed spots in the casting. These would not cure but would remain soft and sticky no matter what.
To be fair, the mold I was using ( the 1 1/2 cabochon mold) is one of the largest mold sizes that is used with Little Windows resin. I'm under the impression that most other craftspeople use this resin to cast smaller pieces, for beads and jewelry and such, and bubbles would have an easier time rising out of smaller amounts of material. I also suspect that if I waited until a warmer time of year when the ambient temperature were higher (it was early spring in VT, and it was in the 60's in the house) I might have had better luck. I also took some comfort reading online that casting clear resin can be tricky for most people to learn.
I briefly considered making eyes out of other kinds of resin, but rumor has it that Easy Cast, another commonly used resin, is hit or miss in the curing department and also yellows over time, and Smooth On's Crystal Clear- what Dreamvision Creations uses for its eyes- is somewhat toxic and as such is not suitable for a home studio. (Plus, when I asked about it, they told me they also use a vacuum chamber to make sure the castings come out bubble free!) When I called Smooth On's excellent tech department to ask what clear casting resin would be suitable to use in a home environment, they recommended Epoxacast 690, with the caveat that the two parts were fussy to mix and I would need a scale that could measure down to 1/100 of a gram. If I do go back to trying to cast my own eyes, this will be the material I start with. However I decided I had spent enough time chasing this rabbit down the hole and I needed to get back to what I was most interested in in the first place: making masks.
I write my tale of woe here so that either a) you my dear reader can either learn from my mistakes and perhaps achieve a bubble free casting where I could not or b) save yourself a lot of time, money and aggravation and proceed directly to Etsy to buy a pair of blank bubble free resin eyes to paint for yourself. Which is what I ultimately wound up doing.