Art Resin Vs Casting Resin: What's the Difference, When to Use What, and Why

I see this question asked a lot in the resin art fan groups online and if you're struggling with choosing which resin to get when you're beginning this art medium as a hobby, this post is for you.


Art Resin


So first thing's first. There are many brands that carry epoxy resin made for art, which they usually call "art resin", and there's also a brand that's called ArtResin.

Art resin as a type of epoxy resin usually has several different properties to it that make it extra appealing for resin artists to use. Essentially you can think of art resin as a coating resin, which means you can use it to form a shiny glass-like layer over top of your existing art work made up of a different medium, like for example acrylics, or you can use art resin together with pigment powders and pastes to create resin art like what you see on my site.


Art resin usually has enhanced UV stabilizers added to the formula, which give resin extra UV protection and keeps resin from yellowing longer. Art resin has a longer work time (usually approximately 40 minutes) than the epoxy resin that's formulated for use on marine boats and other technical applications like that. A longer work time means you can manipulate your resin longer. Art resin is also self-leveling and will create a dome finish.


But as I said above, art resin is a coasting resin, and it is not meant to be poured deeper than 1/8th of an inch. If you do end up pouring it deeper than 1/8th of an inch, bubbles trapped in resin will be a lot harder to get rid of. Deeper pours can also lead to an exothermic reaction, which is when epoxy resin literally gets so hot that it starts to smoke and bubble, and it cures in minutes when a reaction like that occurs.


If you need to pour deeper than 1/8th of an inch, you most definitely need a casting resin. Art resins usually don't have a very good heat tolerance, and so if you intend to make coasters with an art resin you have on hand, a hot mug may leave a ring on it and ruin your creation.


Casting Resin


There are many different kinds of casting resins out there on the market today, so I can't speak for all of them but I will speak of the ones I've tried so far. Casting resins are formulated specifically for casting - for creating resin products by pouring resin into molds or hollow deep cavities (like in wood, etc).


Every casting resin has a different maximum depth that it can be poured in, so please contact your manufacturer to find out what that is for you. I use KSResin Liquid Cast for my coasters, and it can be poured up to 2 inches deep. {Use code UNDILUTED to get 5% off your order, if you'd like to try it}


Casting resins are usually better to deal with when it comes to bubbles but if you want a crystal clear cast every time, you would need to purchase a pressure pot just for your resin art. (Never use a pressure pot that you use for food for your resin art as well!) Liquid Cast resin is the only one I've tried so far that has a nifty feature of 'advanced air release', which means that because it's a slower curing resin, it pushes bubbles out to the surface all on its own and I get nearly perfect casts every time thanks to it.


The only thing I would say that needs improvement in Liquid Cast is that if you pour the minimum depth that they require, which is 1/2 inch, your resin cast will still be bendy and that will never go away. Don't get me wrong, it won't waffle in the wind or anything like that; you would need to apply a considerable amount of pressure in order to bend it! But I like to mention that since most casting resins cure rock hard after 12 hours and this is just a trade off that I embrace with open arms in Liquid Cast as it gives me crystal clear casts in return.


Liquid Cast also has a heat tolerance of 500 degrees Fahrenheit (but I like to stay on the safe side and tell my clients it's safe up to 450 degrees F just in case. 450 is plenty for a coaster I would say!) Casting resin has a lot of other similarities with art resin in that it also has UV stabilizers added to it (though I would say from experience that art resins usually have more UV stabilizers added to them than what casting resins contain), it's also self-leveling and has a high gloss finish. Some casting resins boast longer working time (like Liquid Cast, which I actually love), and some start to get hard after 10 minutes (IMHO, those resins make it really hard to get rid of bubbles). It all really depends on what you prefer as an artist!

 

So to recap:


Art resin's PROs:

- extended work time

- enhanced UV protection

- high gloss finish


Art resin's CONs:

- cannot be poured thicker than 1/8th of an inch

- don't tolerate heat well


Casting resin's PROs:

- for pours deeper than 1/8th of an inch

- great heat resistance (usually!! check with manufacturer)

- UV protection


Casting resin's CONs:

- usually less UV stabilizers than art resins contain

- if poured thinner than 1/2 of an inch, may stay floppy, depending on your brand


IN CONCLUSION:

If you're making something that's super low-profile, like geode resin art or a cheeseboard, go for art resin. If you're making anything that requires a mold, go for a casting resin. :)

 

Whichever type of resin you end up choosing, please remember to use your PPE and take care of your health. Manufacturers make bold claims all the time that their resin is the only one that's non-toxic, fume-less, etc. Always wear an organic vapor respirator when working with epoxy resin.


 

Happy Creating!!


Love & Light,

Alex

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