How to use cookie cutters as resin molds
A wide variety of things can be used as molds for resin. One of my favourite mold types is the mold I create myself with cookie cutters, rubber texture tiles made for working with clay, and Silly Putty. With these three simple things, you can make a variety of shapes with a very unique look.
For this tutorial I’ll be showcasing two different pours to display various techniques for Cookie Cutter Casting. The masque and heart were cast on one day, the other three were cast on a later day.
As odd as it may seem, the best cookie cutters for this technique are metal. Cookie cutters with simple shapes are easier to use.
Small openings, lots of tight bends, internal voids, and other intricate shapes are possible to use but are more difficult both to seal and then to remove the cured resin.
Warning: If you use an item in resin casting never use it for food later. The cured resin isn’t toxic but the resin residue from casting and uncured resin should not be injected. Get two sets of the cookie cutters if you also want to have cookies in those shapes.
Texture Tiles or Stamps:
A texture tile is basically a large rubber stamp. The texture tiles I have are grey rubber and made for working with polymer or precious metal clay. The best kind of texture tile is one with deep impressions and wide openings.
Thin delicate lines may not allow the resin to flow into all the cavities or may trap bubbles. This makes them less suitable for Cookie Cutter Casting.
Tip: If you have a tile or stamp you want to try with this technique, to see if it will work with resin, pour a small amount of resin on the back, the unpatterned side, and let it cure. If you can peel the resin off easily, it should work with resin. If it doesn’t peel off easily, you can try it again with mold release. Should your trials show the tile or stamp won’t work with resin, since you used the back to test it, you haven’t ruined it for other uses.
Yes, the kid’s toy Silly Putty. Resin doesn’t stick to Silly Putty so it makes a great temporary molding material or a great way to seal a gap such as the one between the cookie cutter and the texture tile (or even a hole in found object to use as a bezel).
The colour of the Silly Putty doesn’t matter. I have a couple eggs of Silly Putty I bought at the drug store or grocery store. Over time and use it does get a little less pliable and sometimes bits of colour and glitter inclusions stick to it making a batch less than ideal, but it’s pretty cheap and readily available and many different types of stores.
I’ve never tried using the dollar store knock off brand mostly because it’s really not that much cheaper than the real stuff.
For the projects showcased in this article, I’m using Resin Obsession Super Clear resin. Super Clear resin is a 2-part epoxy resin with 2:1 ratio. This means you need to combine two parts of part A and one part of part B. Super Clear cures to a soft cure in approximately 6 hours when it can often be removed from a mold and set to finish its cure separately. Super Clear cures to fully hard in 12-24 hours.
Because mixed resin has a limited amount of ‘working’ or ‘pot’ time (the time before it starts curing), it is best to prepare the molds for casting before mixing the resin. Super Clear has approximately 30 minutes of pot time.
Because the cookie cutters are metal resin will bond to them unless you use release. You can also use release on the texture tile or rubber stamp to help make unmolding easier.
If you’re using a spray release, you can use a tin foil pan to spray the release. Apply a generous amount of release to the cookie cutters. If the release is liquid allow it to dry thoroughly.
Decoration before making the mold
You can add powders, paste, paint, glitter, and other embellishments to area on the texture tile you will be using for the mold before you put the cookie cutter in place. For some substances, it’s easier to apply them without the cookie cutter walls in the way.
For example, you can use Gilders Paste on the high areas of the texture tile. On the finished piece this will accent the recesses.
Creating the mold
Making the mold is as simple as placing the cookie cutter on the tile and sealing the gap at the bottom with Silly Putty.
Place the cookie cutter on the tile to frame the texture you want to see on your project. If the tile you’re using is narrow, make sure the cookie cutter is entirely on the tile and not hanging over the edge.
Squish the Silly Putty around the bottom of the cookie cutter to make a seal with the tile and create a bezel-like opening.
If you’re using a more intricate cookie cutter, like this masque, make sure you seal each angle and inner cut area, such as the eyes. You can use the back of a paint brush or a stir stick to squish the Silly Putty into those places.
For less complex shapes you can either remove the cookie cutter before pouring the resin or leave it in place. The cured resin is, of course, easier to remove without the cookie cutter. If you choose to remove the cookie cutter, be sure you don’t lift up the Silly Putty from the tile while taking the cookie cutter out. You want to have a complete seal around the area you want to pour. You also want to be careful not to distort the shape.
You can add additional glitter, powders, or other embellishments after you have created the mold.
These are examples of other cookie cutter molds. When you have more than one egg of Silly Putty, you can make more molds at one time. I don’t mix my Silly Putty, I don’t know if that would make any difference in how they work.
Gather all the items you will need to mix and pour the resin before you start. Cover your work surface with a sheet of wax paper to protect your work surface from drips and spills and make clean up easier. Use gloves, such as Nitrile gloves, to protect your bare skin from the sticky resin. For accuracy, it’s always best to measure each part in its own cup.
For Cookie Cutter Casting, each mold will only need a shallow amount of resin. I generally mix 1.5 ounces or less. To make this amount of resin using Super Clear, pour 1 ounce of part A in the first cup and 1/2 ounce of part B (hardener) into the second cup. If you are making a different amount, part A needs to be twice as much as part B. If you are using a different resin, read the instructions that came with the resin to know what ratio you need. If you use the wrong ratio for the parts, the mixed resin may not cure correctly.
If you’re using Resin Obsession pigment, add a small amount to the Part A cup before you mix them together. This picture shows 1/2 ounce of part A with 1/4 ounce of part B to make 3/4 ounce total. Add additional drops of part B, 1/2 of the amount of the pigment, to ensure the proper ratio.
Combine the two parts into one cup and thoroughly stir them together. Mix slowly to avoid adding bubbles. Be sure to scrape the bottom and sides often, and scrape the stir stick as well. Mix the resin for at least 2 minutes to be sure the parts ares well combined. You can pour the mixed resin into another cup and stir for an additional minute to ensure a thorough combination.
Filling the Molds
Pour a thin layer of resin into the molds.
You want to have approximately 1/8 inch (or about 3 mm) of resin in your molds. If you removed the cookie cutter from the Silly Putty, only pour to the depth of the Silly Putty wall. Then, leave the resin to cure in a level location, preferably with a cover. Super Clear works great even when it is poured in a thin layer.
I use wax paper covered low-walled rigid plastic pans (recycled packaging) under my tiles while I am making the molds and pouring the resin. This allows me to move the resin filled molds to a ‘curing location’ where I can cover them and so I can have my desk available for doing other other things while they cure. If you move the uncured resin in molds, be very careful not to spill it. Move slowly so the resin doesn’t slosh over the edges.
For my curing location, I use a pair of cheap plastic letter trays lined with wax paper as shelves for curing projects. Resin generally doesn’t stick to wax paper. If you have a spill, your resin project won’t become a permanent part of your curing location. I also use plant trays as covers for resin items because they’re cheap but keep dust and cat hair out of the curing resin. In colder months, I cover the whole area with a see through plastic bin.
Resin cures best when the temperature is around 74 F (23 C). If your curing location is a bit cooler, the curing time may be increased. If your curing location is a bit warmer, the curing time may be decreased. If it’s a lot colder, the resin may not cure correctly at all.
Under my curing shelves I have a heating pad and tin foil pan to add a bit of warmth to the curing location. Before I even pour the resin, put on the cover and turn the heating pad on to high to warm up the air where the resin will be curing.
Super Clear cures to a soft cure that can be unmolded in 6-8 hours. I like to unmold the Cookie Cutter Castings at the soft cure stage and let them cure to hard out of the molds. This allows more flexible options to remove extraneous bits from the casting.
Unmolding a piece without the cookie cutter is easy. Just bend back the flexible tile and pop the resin piece off the tile and remove the Silly Putty. I always put the Silly Putty back into its egg so I can use it later.
Unmolding an item cast with the cookie cutter still in place takes a bit more effort. First peel the tile off of the resin, just like with the item without the cookie cutter. Remove the Silly Putty from the tile and put it in the egg.
Next, pop the resin out of the cookie cutter. With some shapes, it can be hard to remove the cured item from the cookie cutter. If you unmold when the resin is in a soft cure, you can carefully slip a craft knife around the edges to release the resin. If the resin is cured to a hard cure and is stubborn coming out, putting it in the freezer for 10-15 minutes can help. Applying a good coating of mold release at the beginning of the project makes this stage so much easier.
When you unmold items that have colourant and glitter, the Silly Putty will often pick up some of the embellishments from the tile. These can generally be picked off before you use your Silly Putty again. For this piece, the Silly Putty didn’t have a tight seal on the tile all the way around, so a bit of resin seeped under. This also can also be removed from the Silly Putty.
Triming and Sanding
If you remove your items from the molds when they’re soft cured, you can trim away some of the edges with a scissors.
Place your items on a flat surface and allow them to cure to hard, usually 12-24 hours. Once the items are cured to hard, the edges can be sanded and finished.
To sand the edges of small molded items, I like to use a nail emory board that I’ve picked up at the dollar store as my sanding tool. Go over all the edges of the piece to smooth off any sharp bits.
If you have an item with voids or holes in the surface, you can use a rolled up piece of sand paper to sand them. A grit of 400 or higher is recommended.
Use a wet wipe to remove any stray particles from your sanding before adding any additional finishing.
Once your pieces are sanded you can add paint or Gilder’s Paste if you want additional highlights for the texture.
Adding colourant as a finish may have a slightly different colour than that which is put in the mold at the beginning.
NOTE: Colourant added after the item is cast won’t be as permanently melded with the resin and can rub off with wear.
Every unmolding is like uncovering a unique treasure. Some items look great on both sides without any additional finishing touches.
Stay tuned for next week’s post as Kate shows you how to make your castings into wearable jewelry or use for another art project.
So what do you like best about this tutorial on how to use cookie cutters as resin molds?