Smooth-Cast Onyx Slow - Ultra-Black Urethane Resin - Pint Unit

I don’t know why the review asks for sheerness as this material is solid black. No adding dyes needed. Works well for cold casting, resin casting, and gives you just enough time to place it in a vacuum chamber to remove air bubbles.

The product works well and has a nice finish. Gives you plenty of work time witch is great if doing multiple pores. It only has 1 flaw, it will take about 45 minutes longer than advertised.

Any of the onyx brands are usually really good. Pretty comparable for the strength of the product compared to durability

This is unforgiving, mislabeled, and described inaccurately, it's really more of a hassle than anything. First off, the cure time is way off in the description, it says 90 minutes, but it's more like 2-3 hours. This stuff is VERY finicky, and very unforgiving. If you don't stir and mix this stuff like crazy it will never fully cure and be a sticky, oily, gooey mess forever. With regular smooth cast, you stir it and mix it a healthy amount and it works, but this stuff you need to mix literally for minutes straight, and the worst part is the pot life is short. They say it's "slow" curing, hence the name Onyx-Slow, but the pot life is about 4-5 minutes tops, it's NOT 7 minutes. You have 4-5 minutes to pour this stuff, and you have to stir it for over one minute, so really you get 3 minutes of actual pouring time before it locks up.And I kid you not, if you don't stir the mighty hell out of this stuff, it will not cure and be an oily mess. So really, this onyx-slow has all the drawbacks and none of the pluses. It has a super short pot life that is not accurate to the description, a pretty long cure time that is way longer than the description, and costs more money. So really, what do we get out of this other than it's black? I'll never use this one again, I'll stick with regular smooth-cast and just add pigment or dye or paint it later, it's a superior product.messy, misinformed, hassle of a product. Shame too, because I thought a black casting plastic from smooth-on would have been AWESOME, but it wasn't.

Great product, however I am noticing less volume in each bottle compared to previous purchases. Also the film sealant under the cap has gotten thinner and cheaper.