How to Make Silicone Molds

How to Make Silicone Molds


The key to a beautiful resin casting is having the perfect negative mold, so this should be one of your top priorities.

You can buy many kinds of molds, but silicone is the best and most beginner-friendly. The flexible and supple material allows you to create complex and unique castings without much hassle.

This article will discuss silicone molds and why you need to consider them for your next resin project.


Silicone molds are reusable epoxy molds made primarily from silicone rubber: a durable yet elastic material. When using silicone molds for resin, the silicone’s flexibility makes it easy to remove the casting.

A critical property of silicone molds is the degree of hardness, usually measured in Shore. 

A lower Shore (0 – 20) makes a softer mold that’s easier to remove from your casting. However, overall, it is less stable and won’t hold its shape for long. 

A higher Shore (40 – 80) results in a more rigid mold that better retains its shape, but you’ll find it harder to remove the object from the mold. These molds are also prone to breaking when you apply too much force while removing the casting.

Epoxy resin molds with a moderate Shore (20 – 40) offer the best of both worlds, giving you stability and reasonable flexibility.

There are plenty of ready-to-use molds available in the market. A resin mold kit is also a great option. However, for creating unique objects, nothing beats having your own custom silicone molds.

Read on as we discuss how to make your DIY silicone mold.


There are two ways on how to make resin molds—either with or without a template. In both methods, you’ll use a “blank” to determine the empty spaces of your mold. 

A template is a kind of frame that contains silicone to prevent it from overflowing when you pour it. You’ll place your blank in the template frame and then pour the silicone over it. After the silicone hardens, you can simply remove the mold from the frame. A template is helpful if you’re creating duplicate molds to ensure each one is the same size and shape.

You can also create a mold without a template. 

In this method, you place the silicone in a mixture of water and detergent so it remains pliable. Then, you take the silicone and wrap it around the blank, ensuring you sufficiently cover all areas. Depending on what shape you are trying to achieve, you can either leave an opening so you can remove the object later, or you can cut the mold after it hardens.


Now we get to the main event—a step-by-step guide on how to make a mold. In this example, we’ll be using the template method.

  1. Construct the frame or template. It should be 100% tight (free of cracks where silicone could seep out) and  allow ample space for silicone to flow around the blank. You can use any material to create the template, except for glass. A smooth MDF board is a popular choice.
  2. Once the frame is ready, place the blank inside, making sure the side to be pictured on the mold faces upward. Fasten the blank to the frame’s base using glue or tape so it will not move when you pour the silicone.
  3. Prepare the silicone according to the manufacturer’s instructions. It would be wise to measure how much you’ll need in advance.
  4. Release any air bubbles on the silicone mixture by tapping the bottom of the cup on the tabletop.
  5. If you’re using a wood frame, coat the inside walls with a release agent or a silicone-compatible oil. 
  6. Pour the silicone on top of the blank. If it has many edges, nooks, and crannies, you might need to fill these first using a thin silicone jet before pouring in the rest.
  7. Fill in the rest of the frame with silicone. Tap the sides of the frame to remove any air bubbles.
  8. Allow the silicone to harden. This process varies from 1 – 24 hours, depending on the size and shape of the blank.
  9. Gently remove the silicone mold from the frame and take out the blank.
  10. Straighten the edges using a pair of scissors or a scalpel. You can also rub the silicone mold with talcum powder to keep it supple.


Silicone molds are one of the most accessible molds to work with, especially for beginners, due to their flexibility. You can create complex shapes for your casting and still easily remove your final work.

This kind of mold is also readily available in a variety of shapes. Or, if you want to get creative with your casting, you can make molds yourself. This DIY process allows you to make anything you wish.

As a material, silicone is non-toxic and doesn’t cause any allergic reactions. Therefore, you can safely use it for a variety of projects.


Plastic Materials Incorporated has all the materials you’ll need to create your silicone molds and epoxy resin castings. Contact us today or visit our website to find our complete selection!

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