Five things you should never set in resin

Things you should never put in resinAdding things to resin is an easy way to make your resin crafts and jewelry special. Your possibilities are endless! While there is so much you can add to resin, there are five things you should never set in resin:

Fresh flowers

Fresh flowers will turn colors in resin. They can do anything from go clear to turn brown after putting them in resin. If you want to use flowers in resin, you will need to dry and preserve them first. You can learn to do that here: How to dry flowers for using in resin

Anything you think you might want to get back out later

While photos, mementos, and heirlooms look great when embedded in resin, think twice before putting them in a resin casting. It will be almost impossible to get the item back out of the resin without destroying it in the process. Instead, make a copy of the thing if possible (especially easy in the case of photos, tickets, notes, etc.) and include that in the resin.

Fresh food

Fresh food items with high water content, like fruit, will rot and turn disgusting in resin. You must dehydrate the food first, and even then, it’s difficult to get all the moisture out to keep the food from rotting. This extra moisture will also keep your resin from curing. What can you do instead? Create a food lookalike with clay. Clay and resin go great together! You can see what I mean here: How to make a resin and polymer clay ring


Resin hates moisture, and some resins, like polyurethane resins, hate it more than others. It’s why I stress using colors explicitly designed for resin because the moisture in paints and food colorings can keep the resin from curing. If you want to change the viscosity of your resin, solvents like alcohol and acetone work better and are less likely to impact curing.

Bugs and other small specimens that aren’t entirely preserved

Like flowers and fruit, small animal specimens will rot if included in resin without preserving first. We have a great discussion about this topic in our forum that will get you inspired to give this project a try. How to embed a spider in resin.

And if you are looking FOR things to put in resin, I’ve got ten ideas for you here: 10 things you can put in resin jewelry 

What else have you set in resin only to find out it was a complete disaster?

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38 thoughts on “Five things you should never set in resin

  1. Very helpful! it is especially important to note that while acrylic paints can be used to color resin. Not all acrylics work well due to the water content and it would be a real bummer to find out the hard way that your acrylic paint had too much water in it. Hi flow, student grade, and many craft acrylics have to much water content. The professional grade acrylics that come in tubes (like toothpaste) have less water but you may want to add acetone or alcohol to them before mixing with resin because they are more difficult to fully incorporate, though if you are looking to add texture this can give you raised area of color.

    1. Great advice here Ilene. Trying acrylic paints is fun but can give variable results. Thanks for sharing your guidelines!

  2. I read in your article that changing the viscosity of resin can be achieved by adding alcohol or acetone. I have been wanting to try that but was not sure if it would work. I imagine that only a very small amount should be used. Am I correct? I have a project and want the viscosity very thin with this one particular project. Thank you, Katherine Swift, for always steering us in the right direction when it comes to resins and making things using it. -Loretta

    1. Thanks Loretta for the kind words! If you want to try using acetone or alcohol, add no more than 1 part solvent to 10 parts mixed resin. Use even less if you can.

  3. Thank you for your e mail, but to late, my flowers I carefully picked ,turned brown. Thank you this is just the info I need!

    1. Hello and Happy Thanksgiving To All,
      Enjoy your day! Ok so Forgive me ,if someone has already replied with the same reponse as me but pick your flowers from your own garden or buy some for your particular epoxy project cut them as normal and immediately hang them upside down (all the colors for the most part) will drain into the flowers and leaves and because gravity doesn’t play a noticable part an added bonus is that they will dry opened as though in bloom with minimal wilting.
      You’re Welcome, 🙂

  4. following up on what loretta posted, i’d love to know how to decrease the viscosity as well… can you basically make a doming resin out of a high-viscosity resin? (just waiting for it to thicken before curing hasn’t worked for me.)

  5. I advise using alcohol inks or pigment powders instead of acrylic paints so you will NOT have a situation and not worry about it. Both last forever so they are cost effective and easy to use.

  6. Hi Katherine
    Have you any experience with using different resins within resins? For example, a feature element of polyurethane with polyester resin. :I’m wondering if they can be used in the same pour?

    1. Hi Marcy, thanks for sharing your experience. While using a pressure pot is a great way to get bubble-free castings, I’m afraid it isn’t going to do anything to change the flowers. They will eventually rot if not properly preserved first.

  7. Hi Katherine,
    How do you cure in a pressure pot? I have heard about it, that you will have 0 bubbles but know nothing else.
    Thank you. Love your work.

    1. Hi Ramona, you are right about using a pressure pot to remove bubbles. I’m afraid we don’t have an article currently, but I love your suggestion!

  8. I am making mosaic trays finished with resin coat to create smoother surface. I know I need more than one coat to level the surfaces. On one of the trays I let the 1st coat cure for 24 hours, sanded and poured the 2nd coat. On the other I waited 5 hours and poured the 2nd coat over the still sticky 1st coat surface. The 2nd coats for both trays were poured from the same mixture at the same time. The tray that was sanded has cured and hardened. The 2nd tray is still sticky a day and a half later. Can you recommend a way to fix/save this 2nd tray?

      1. I am making mosaic trays finished with resin coat to create smoother surface. I know I need more than one coat to level the surfaces. On one of the trays I let the 1st coat cure for 24 hours, sanded and poured the 2nd coat. On the other I waited 5 hours and poured the 2nd coat over the still sticky 1st coat surface. The 2nd coats for both trays were poured from the same mixture at the same time. The tray that was sanded has cured and hardened. The 2nd tray is still sticky a day and a half later. Can you recommend a way to fix/save this 2nd tray?
        Not sure if I am doing this followup correctly.
        Wondering if my problems with my trays (approx sizes 24″. by. 12″ has anything to do with the quantity of the pour? You are dealing with small pieces like jewelry whereas mine are considerably larger. I doubt that the quantity itself effects the cure since one tray cured well but the other is sticky. Would mixing larger amounts require longer mix times and cure times?

  9. Hi! Thinking on trying some resin crafting and doing my research before I dive in. Was wondering if sanding down some pastels (not oil) into fine powder would work as a colorant, like your chalk experiment? Also, with quality acrylic paint could you paint something straight on the resin between layers perhaps?

  10. Just starting to play with resin and was wondering how emollient products like lipsticks and cream makeup and blushes would go being encased in resin? Would they have issues in regards to degeneration? Wouldn’t be using them to try & color the resin. Any advise, much appreciated. Hope all safe & well over there

    1. Hi Michelle, I’m not sure how well lipsticks and creams would mix into resin. Resin doesn’t mix well with oils.

    2. I would purchase a little clear case of sorts to put your liquid into or lipstick if that suits… somewhat like for coins, then they can be submerged into the resin without a problem. Or, if you are wanting to place in a fully formed lipstick piece, I would suggest to first give it a fine coating and allowing it to harden first before submerging the whole thing into the resin. Resin can heat while curing and this may be enough to melt lipstick. I always say, I’ll try anything once, if it fails dramatically you could either learn from it and try again, or think of another way. Good luck

  11. I once had a work colleague find a dead baby bat and requested I set it in resin. The bat, when found, was as hard as a plank of wood, so presumably it was dead for a very long time…. BUT when I placed it in resin, the heat from the resin began to cook it, and proceeded to smoke slightly and emit an awful stench! It also bubbled slightly and caused its blood innards to protrude, causing a set in air pocket with the visible liquid. … in the past I had done many insects and bugs and spiders, but the bat was by far the worst! And I swore never again to do anything bigger than an insect 😳

  12. I am a retired vet and decided to do some wood work, while sitting ad relaxing in my field. The results were very nice and when I saw in the internet the resin works l was very excited, so l gave it a start. Every body is really excited with my results especially when I was using olive wood with resin. Today l saw your site and thank you very very much for your advices . The problem l came across, especially when I tried to do a dining table using olive wood and resin with excellent results, was the price of the resin in my country. 550€ for 20 liters. What about the price in your country and how can I get it to Cyprus? Thanking you in advance……….

  13. I made the rookie mistake of trying to cast a giant leopard slug in resin when I was first trying this.
    Disaster! Disaster! Disaster! It disintegrated into a greasy looking pulp before the first layer even hardened. Not to mention was the grossest thing I’ve ever seen and I had to throw it in the trash. Lesson learned!

  14. I am also new to resin and am learning fast from my mistakes. I am casting my backyard flowers in various molds. I am having trouble handling the more delicate dried flowers, like Cosmos, from silica or pressed. I tried acrylic spray but how do I dry them? How do I keep from blowing them away? Etc. Some are like tissue. I made a matte medium from white glue and water but I couldn’t find a spray bottle that gave me a fine enough spray. Maybe some flowers are not meant to be preserved.

  15. My husband found a beautiful dead butterfly and wanted me to put it in a round coaster mold. I did, it turned black and when I used the torch for the bubbles it wanted to catch on fire. I’ve learned my lesson. Thanks for your suggestions and help. No more bugs!

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