What You Should Know About the Types of Epoxy

What artists should know about epoxy resin types
It makes total sense when creating with resin that your first step is choosing a resin.  Like you can’t make a resin project without the resin. But maybe you’ve never worked with resin, and you don’t know where to start. With so many types of epoxy resin, how are you supposed to know which one to use?

Or maybe you didn’t even realize there are different types of epoxy resin.

But, hey. What does it matter. Because one resin can make anything, right?

Unfortunately, no.  There is no one-size-fits-all all resin.

Making something beautiful means understanding the differences between epoxy formulas BEFORE you buy resin so you can choose the RIGHT one for what you’re making.

What’s the difference between the types of epoxy resin?

Here’s the BIG thing you need to know:

There are two major types of epoxy resin:  Doming and Casting

A doming resin mixes thick so it finishes with a smooth, even surface on your project.

These are meant for coating a surface.

Doming resins are also what you want to use when you make an epoxy tumbler or need epoxy for a tabletop. The surface tension of doming resin is such that it wants to finish uniformly. They’re also great for getting a dome on jewelry blanks.

A casting resin mixes thin, making it easy to release bubbles.

These resins are meant to be poured into something that will contain the resin.

This could be resin molds or an open space to make a resin river table.  This thinner viscosity is what makes casting resins ideal for spreading into all the intricate parts of a mold.  They also have the advantage that they release bubbles easily, making them ideal to pour in deep layers.

When would you use a doming resin?

A doming resin mixes thicker and will stay on the surface of something. For example, if you want to make epoxy art, you want a doming resin so that it will produce a glossy surface on your resin painting.

Doming resins are also important if you want to make jewelry with a domed finish.

When would you use a casting resin?

Casting resins are meant to be used for just that – casting. You should pour them into something that has sides to be able to contain the liquid. They can be poured into deep layers if desired. Comparing both types of epoxy, removing bubbles from casting resins is much easier than doming resins.

For small jewelry projects in molds, you want something that will cure clear and durable.

When making larger projects like sculptures, deep paperweights, and river tables, a slow-curing formula that you can pour in thick layers is ideal.

Can you use doming resins and casting resins interchangeably?

Sure. If you’re one of those people who think butter and margarine are the same thing.

The resin doesn’t know how you’re using it. It only wants to do what it’s designed to do.

That means you shouldn’t pour doming resins more than an eighth-inch deep (the depth it wants to self level to). While you can pour them in thicker layers, it’s harder for all the bubbles to release before it starts curing. Plus, when you use doming resins in molds, they can cure bendy.

A casting resin can be applied to a surface without sides, but because it mixes thinner, it won’t spread out evenly.   If you use it to coat a large surface, you’ll get ‘fish eyes’ and voids in your surface.

What should I notice when I’m mixing these resins?

Doming resins will mix like the consistency of syrup. Casting resins will mix mix thin like water or rubbing alcohol.

How do I know which of the epoxy types I’m buying?

When you buy a resin, it will be one or the other. For the resins sold on Resin Obsession, we have that information in our free resin buying guide.

💡 Pro tip: If a resin tells you that it’s both, then treat it like a doming resin and don’t pour it more than 1/8 inch deep in molds.

Can I apply multiple layers of doming resin or casting resin?

Both can take additional layers. You can wait until the previous layer is fully cured before applying the next layer, or if you only wait until the previous resin layer starts to gel, you can pour the next layer and minimize the lines between them.

If you want to see differences between the types of epoxy, this video shows more:

Want to learn more about the types of epoxy?

Then you will want a copy of Resin Fundamentals.  I explain everything you need to know about resin in clear and concise details.  It’s the ebook I wish I had when I was a resin beginner!  Buy the PDF book now, and you’ll get an email download link in minutes.

Unpublished Blog Posts of Resin Obsession, LLC © 2023 Resin Obsession, LLC

Like this post? You may be interested in  How To Resin A Painting Without Breaking A Sweat

46 thoughts on “What You Should Know About the Types of Epoxy

  1. I’ve been trying to coat polymer clay earrings that I put an image on to (baked in) with the doming resin and find that many times when I think I’ve put enough on it starts to pull back from the edges (no rims on the earrings) or leaves a dry spot. If I try to correct this after the resin hardens it doesn’t blend in. Any suggestions? BTW this video is great.

  2. Let’s say I want to add a dome to something that I have cast, can you use a doming resin on top of a casting resin?

  3. I have seaglass, small shells and some pottery shards glued to an old window and want to use resin like grout for the mosaic. I am still not sure if I need doming or casting. I have not used resin before

  4. Why can’t you use some resins on wood? I’ve got a table and the top is timber Pailings with a gap between each one. I know it’s a design feature but it’s not good for crumbs. I want to pour resin into each gap. But I think I’ve bought the wrong product. It’s called Kleer Cast by Norski

    1. Some resins shrink too much after curing and can pull away from the wood. What kind of resin is Kleer Cast? I’m not familiar with that one.

  5. if my resin is gooey after curing time what do I do, or what can I do. I did a 6 pane window with seaglass I want to hang inside but it i hang it will it run?

  6. Hi, and thanks for all the helpful advice above.
    I am trying to make some drink coasters on ceramic tiles. The painting part is fun and works out well. However, I can’t get any resin to go hard enough to withstand a hot coffee cup without getting indentations from the cup base. Even after 2 weeks it still happens. The only doming resin in my local (ie. New Zealand) hardware store is by Norski. I have also tried a casting resin and a clear polyurethane varnish. Any ideas?

  7. Thank you for responding, your answer really helped. I am VERY new to this, but I’m also very eager to expand my creative side with resin! After watching your vid, I also learned that I’m going to have to make a contraption of some sort to rotate the piece (a mannequin head) 180 degrees throughout the process which will be tricky because I need the resin to cover the entire piece, top of the head to the base.

  8. I have mistakenly bought the casting resin to seal artwork. One coat and I see the non coverage. If I put another coat of this resin will it eventually make a smooth coverage? Or do I have to get some doming resin to do the next coat?

  9. I did a 1 7/8″ wide x 1″7/8 H x 3 1/8 long paper weight with Amazing Clear Cast resin. I did the pouring into the silicone mold (I made) in 2 sections. I poured the first mixed portion and waited about 8 hours before I poured the second mixed resin portion. The outside shape came out great and shiny but I had “tons” of very small bubbles. While I was mixing, I put the mixing cup in hot water (from the faucet) to minimize bubbles. I also used a butane candle lighter on the surface to also pop any air bubbles that came to the surface. After 10 minutes in the mold, I use a few light spritz of spray of isopropyl alcohol, again to pop any bubbles that came to the surface. I read about using a fire torch or a candle flame lighter, the warm/hot water in a bowl and the spray of alcohol from various readings and videos, and I did all these. But I still got “tons” of tiny bubbles – help!

    1. Hi Teresa, I’m sorry this happened to you. Because of the mixing thickness of the Amazing clear cast resin, it likes to hold onto bubbles. It’s very difficult to get a bubble-free casting when using this resin in pours of greater than 1/8 inch. Instead, one of our clear casting resins is a better fit. For pours of 3 ounces or less, the Resin Obsession super clear resin is what you want:  https://shop.resinobsession.com/collections/resin/resin-obsession-super-clear-resin
      For pours of 3 ounces or more, the Resin obsession deep pour casting resin works great:  https://shop.resinobsession.com/collections/resin/resin-obsession-deep-pour-resin

  10. Hi! I want to use clear doming resin to seal shrinky dinks. They have irregular shapes, and they’re also typically decorated with either colored pencil or alcohol marker.

    Is there anything I need to do to protect the designs? What do you recommend for a beginner?

    I included a link to my products. I currently seal them with embossing powder, but find it can cloud the image a bit.

  11. I am currently making epoxy resin cheese boards,the problem I have is that the epoxy only leaves a very thin layer on the sides with very little color..do I need a thicker epoxy resin?

    1. Hi Wayne, unfortunately, it’s the nature of epoxy resin to drip off the sides. While a thicker resin will help, it’s not going to be as thick as the top of your cheeseboard.

      1. Hi Katherine,
        I have never worked with resin and am doing as much research as possible prior to doing my first project. I’m working on an rv remodel and am going to be installing loose pebble flooring. Everything I’m seeing online (which, unfortunately, isn’t much) looks like the flooring is finished with a flat surface. My intention is to have a pebble texture. After reading a little on you’re awesome site and watching your video, I have A LOT of questions. It seems I need casting resin for the texture but that to keep the pebbles from spreading past the flooring I need the doming. Should I mix the pebble in doming and, if so, will it automatically dome or will the pebble provide enough variation in the surface that it will keep some texture once poured/spread? If it will keep some texture, is it OK to then coat with casting resin and keep the texture? Or, should I mix the pebble in casting to maintain texture and then to coat with more casting? If I mix in casting will it be strong enough and/or will I need to build a temporary border along the sides of the floors to keep it in place? Also, I’m covering approx. 700sq ft and planning on doing it in sections. How do I keep the sections looking continuous and not segmented? Thank you for taking the time to share your knowledge! And apologies for requiring so much of it!
        Best, Leslie

  12. Hi!
    Does anyone know if this Casting Resin turns yellow over time?
    I love working with Polyester resin because it’s harder, never goes yellow, and has less bubbles then Epoxy… but I also wanna try something different.

    I’m worried about the yellowing… Does anyone know about it?

    Thank you!

    1. Hi Isabelle, unfortunately, all resins, whether polyester or epoxy, will yellow over time.

      1. Hello,
        I’m a wood turner and have some logs that dried too quickly and, as a result, have cracks that are approx 1/8 to 1/4 wide. I just want to fill the cracks so I can turn them on the lathe. What would you recommend for this, casting or doming? Thank you, in advance, for your response!

  13. Hi, i am from Mumbai, India, and resin sculpture & art are rudimentary here having missed the resin popularity wave evident in the US & Europe, or even China for that matter. My facination with the infinite wonders i yearn to create with resins is at odds with my zero knowledge & experience in this field. I would appreciate if you guys have some tutorials or PDF docs i could dip into pro bono. Warm Regards, Nikhil Barchha.

  14. Trying to make a beach scene for a wedding. Do I use two different epoxy’s? One for mixing and setting then the other to seal?

  15. Hi, thanks for the explanation about casting and doming resin. I’m a beginner (“resin rookie” 🙂 ) to this creative field (from years of paper craft and printing) – and want to do some doming – and have been devouring YouTube videos. Is UV resin suitable for doming, to be then UV cured, vs a 2-part epoxy resin?

    PS: You have some great molds that are now on my list to get! Glad you can ship them internationally. (I did get the coupon link from “reading the fine print” 🙂 — but that page didn’t have a newsletter sign-up form).

    1. Hi Dean, I’m afraid UV resin isn’t my thing. But from what little I’ve used it, I wouldn’t expect it to dome. And I’m glad that you were able to get your coupon code. 😉

  16. Resin or epoxy resin is a synthetic resin that can be used for many different purposes. The epoxy is created by mixing two components that are matched to each other. When the liquid resin is mixed with a suitable hardener, a chemical reaction is set in motion, which usually lasts several hours.

  17. Hi , I am a beginner at this and want to now. If I want to put a dried flower in a square 2 inch mold. Do I need is there a different type of resin that I should use like a deep pour or can I use any type of resin?

  18. Hello, my mom was given a handmade stained class memorial piece with dads name on it. it’s 12.5 x 13.25 inches. It fell from the window it was hanging from and though it’s together there are small cracks throughout. I was thinking of encasing it in resin and making a little stand it can fit into once it’s done and still sit on a window sill. I do plan on doing some testing since I only have one shot to get it right but I’d like anyone and everyone’s feedback on it. Other ideas, things to look out for, things I should NOT do. Thank you all.

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