How to Make a Silicone Mold Yourself: A Step-by-Step Guide for Beginners

Ready-made silicone molds are convenient, but it is not always possible to find a mold in the exact size, shape, or design you need. Sometimes you may want to reproduce a particular decorative element, create your own mold for a candle, coaster, or figurine, make a series of identical pieces, or turn an original master model into a fully functional reusable mold.

In these cases, you can make a silicone mold yourself.

You do not need complex industrial equipment to do this. For a basic project, you will need a suitable silicone for mold making, a master model, a simple sealed mold box, a mixing container, and electronic scales.

In this article, we will explain in detail how to make a silicone mold yourself, which silicone to choose, how to prepare the model and mold box, how to mix and pour the silicone correctly, how to minimize bubbles, and what to check if the silicone does not cure.

What Is a Silicone Mold?

A silicone mold is a flexible mold whose inner surface precisely reproduces the shape and texture of the original object, known as the master model.

Once the silicone has fully cured, the master model is removed and the resulting mold can be used for repeated castings.

Depending on the properties of the silicone itself, these molds can be used with:

• epoxy resin;
• acrylic composites such as NATURESIN;
• plaster;
• wax;
• soap;
• cement and concrete;
• polyurethane and other casting materials.

Liquid silicone flows into small recesses and accurately reproduces surface texture, while its flexibility makes it possible to remove finished pieces even from relatively complex molds.

This is why making your own molds is particularly useful for makers who want to create original designs instead of being limited to commercially available molds.

When Does It Make Sense to Make Your Own Mold?

Buying a ready-made silicone mold is often the easiest solution. However, making your own mold makes sense when:

• the shape you need is not available for sale;
• you need a non-standard size;
• you want to reproduce an existing decorative object precisely;
• you plan to make a series of identical pieces;
• you have created your own master model;
• a professional ready-made mold for a particular project is too expensive;
• you need to change the depth, thickness, or construction of the future mold.

For example, you can make your own mold for a coaster, candle holder, decorative figurine, bas-relief, small tray, decorative element, unusually shaped candle, or an original epoxy resin piece.

Before mixing the silicone, however, it is important to choose the right mold-making method.

Which Silicone Should You Choose for Mold Making?

The word "silicone" refers to several different types of material. To make a high-quality mold, it is important to use a two-component silicone specifically designed for mold making, rather than construction or sanitary silicone from a tube.

For creative projects, two options are particularly useful: liquid silicone and silicone putty.

Liquid Silicone

Two-component liquid silicone is mixed immediately before use and then poured around the master model.

Because of its fluid consistency, it can penetrate small recesses and accurately reproduce surface details. This makes it particularly suitable for one-piece poured molds and models with complex relief.

M | Art Studio offers Pure Mold, a two-component translucent platinum-cure silicone. For the product available on our website, components A and B are mixed at a 1:1 ratio, and the specified curing time is approximately 8 hours.

Platinum silicones are valued for their high level of detail reproduction, low shrinkage, flexibility, and dimensional stability of the finished mold.

For most beginners, liquid silicone is one of the easiest materials to understand when making a classic poured mold.

Silicone Putty

There is also another method.

I-GUM has a thick, moldable consistency. Instead of being poured into a mold box, it is applied directly to the master model or used to create an impression.

The two components are mixed at a 1:1 ratio by weight until a completely uniform mass is obtained.

One advantage of this material is that small objects often do not require a sealed mold box at all. Silicone putty is also convenient for vertical surfaces, reliefs, and individual details.

We will look at this method separately later in the article.

Platinum-Cure or Tin-Cure Silicone: What Is the Difference?

Mold-making silicones generally fall into two main groups:

condensation-cure silicones, commonly referred to as tin-cure silicones;

addition-cure silicones, commonly referred to as platinum-cure silicones.

Tin-cure silicones are generally less expensive and are suitable for many standard mold-making applications.

Platinum-cure silicones offer excellent dimensional stability and very low shrinkage, reproduce fine details well, and are suitable for repeated use. Pure Mold belongs to this group.

However, platinum silicone has one important characteristic that must be taken into account: its curing process can be affected by certain materials and contaminants on the surface of the master model. We will discuss this in more detail below.

What You Need to Make a Silicone Mold

For a simple one-piece mold, prepare the following:

1. A master model

This is the object whose shape you want to reproduce.

2. Two-component liquid silicone

For example, Pure Mold.

3. Electronic scales

The component ratio must be measured accurately.

4. A mixing container

It should be clean, dry, and large enough to mix the silicone comfortably.

5. A mixing stick or spatula

It is important to scrape the sides and bottom of the container thoroughly.

6. Materials for the mold box

These can include smooth plastic sheets, acrylic sheets, suitable plastic containers, or even LEGO bricks for small models.

7. Material for sealing the joints

The mold box must be completely leak-proof, because liquid silicone can escape through even a small gap.

8. Nitrile gloves

The work area and tools should remain clean.

Depending on the project, you may also need a release agent, a material for sealing porous master models, and a vacuum chamber for removing air from more advanced professional castings.

Step 1. Choose a Suitable Master Model

The quality of the future mold begins not with the silicone, but with the object you intend to reproduce.

Silicone reproduces surfaces very accurately.

This means that it will copy not only attractive texture and detail, but also:

• scratches;
• chips;
• sanding marks;
• wood grain;
• 3D-printing layer lines;
• surface irregularities;
• dust and small particles.

For this reason, the master model should be carefully inspected and prepared in advance.

If you want the pieces produced from the mold to have a smooth, glossy finish, the original surface should also be as smooth and well finished as possible.

Silicone does not correct the surface of the master model. It copies it.

Porous Master Models

Plaster, untreated wood, some types of stone, cement, and other porous surfaces should preferably be sealed with a suitable coating before molding.

This not only makes mold release easier but also prevents silicone from penetrating the microscopic pores of the surface.

Any coating applied to the master model must be completely dry before pouring the silicone.

Step 2. Check the Geometry of the Model

One of the most important stages, and one that beginners often overlook, is determining in advance how the finished mold will be removed from the master model and how the cast piece will later be removed from the mold.

For a simple flat object, a one-piece open mold is usually sufficient.

For example:

• a coaster;
• a small tray;
• a decorative tile;
• a flat bas-relief;
• a pendant;
• a decorative element.

However, if the object is three-dimensional and has projections, deep undercuts, handles, enclosed areas, or complex geometry, a standard one-piece mold may not be sufficient.

In this case, you may need:

• a cut mold;
• a two-part mold;
• a mold with a technical cut;
• an additional rigid support shell for the soft silicone.

For your first handmade mold, it is better to choose a relatively simple object without complicated undercuts.

Step 3. Prepare the Master Model

Before starting, the surface should be:

• clean;
• completely dry;
• degreased if necessary;
• free from dust;
• free from loosely attached decorative elements.

If the master model consists of several parts, make sure they are securely fixed together.

If the object will stand on the bottom of the mold box, it should also be secured in place. Otherwise, a lightweight model may shift or float when the liquid silicone is poured.

Take particular care to secure objects made from plastic, foam materials, and other lightweight materials.

Step 4. Be Aware of Possible Platinum Silicone Cure Inhibition

This is an important technical point.

Platinum silicone may fail to cure when it comes into contact with certain materials. This is known as cure inhibition.

As a result, most of the silicone may cure normally, while the area that was in contact with the master model remains sticky, soft, or liquid.

Potentially problematic materials for platinum silicones can include certain sulfur-containing modeling clays, latex, tin-cure silicones, some paints, polyurethanes, polyester materials, and certain types of 3D-printing resins.

Therefore, if you are unsure whether the material of your master model is compatible with platinum silicone, do not immediately pour a large quantity of material over an expensive or important model.

Perform a small test first: apply a small amount of mixed silicone to an inconspicuous area or to a sample made from the same material and allow it to cure completely.

If the surface remains sticky after the specified curing time, the compatibility issue should be resolved before making the main mold.

Step 5. Build the Mold Box

The mold box is a temporary container that holds the master model and the liquid silicone during pouring.

It has three main functions:

1. to contain the liquid silicone;
2. to maintain the required geometry of the future mold;
3. to be easy to disassemble after curing.

For a small project, you can use a ready-made plastic container of a suitable size.

For non-standard models, it is convenient to build a box from sheet plastic, acrylic, or other smooth materials.

Another simple option for small molds is to build the walls from LEGO bricks.

How to Choose the Size of the Mold Box

Do not make the box much larger than the master model.

The more empty space there is between the model and the walls, the more silicone you will use unnecessarily.

At the same time, the walls of the future mold should not be too thin. The mold must maintain its shape and withstand repeated demolding.

For a small object, it is generally advisable to leave a reasonable amount of silicone around all sides of the model, as well as a sufficient layer above its highest point.

The exact thickness depends on the size, shape, and complexity of the object.

Step 6. Make the Mold Box Completely Leak-Proof

Liquid silicone can escape through surprisingly small openings.

Before pouring, carefully check:

• the corners;
• the joints between the walls;
• the connection between the walls and the base;
• openings around any fasteners;
• gaps beneath the master model.

It is best to check the seal before mixing the components.

Once the silicone has been prepared, there may not be enough time to calmly repair a leaking mold box.

This is one of the most common and frustrating mistakes when making silicone molds yourself.

Step 7. Consider the Surface of the Base

This step is particularly important when making coasters, trays, and other flat molds.

The surface on which the silicone rests will also be reproduced in the finished mold.

If you need a flat, smooth surface, it is better to use smooth plastic, acrylic, plexiglass, or a special glossy film designed for molds and mold boxes.

This is why the quality of the base directly affects the surface of the future cast piece.

For large flat molds, you can also use a combined construction: create silicone walls and use a smooth sheet as the base. This approach can help reduce silicone consumption.

Step 8. Calculate How Much Silicone You Need

It is better to prepare slightly more material than to discover halfway through the pour that you do not have enough mixture.

For a rectangular mold box, you can roughly calculate its internal volume using:

length × width × pouring height

From this volume, subtract the approximate volume of the master model.

For complex objects, an exact calculation is more difficult, so it is useful to allow for a small extra amount when making your first mold.

However, there is no need to prepare an excessive amount. Once the components have been mixed, curing begins, and unused mixed material cannot be returned to the original containers.

Step 9. Weigh the Components Accurately

For Pure Mold available from M | Art Studio, components A and B are mixed at a 1:1 ratio.

This means:

100 g of component A + 100 g of component B;

250 g of component A + 250 g of component B;

500 g of component A + 500 g of component B.

Use electronic scales.

Do not measure the components approximately, particularly when making a large mold.

An incorrect ratio can affect both the curing process and the properties of the finished silicone.

Step 10. Mix the Silicone Correctly

Combine components A and B in a clean, dry container.

Mix slowly and thoroughly.

The goal is to obtain a completely uniform mixture while introducing as little additional air as possible.

While mixing, make sure to:

• scrape the sides of the container;
• scrape along the bottom;
• bring material up from the lower layers;
• avoid whipping the mixture with fast movements.

A common mistake is to mix silicone vigorously in the same way you might mix paint.

This introduces numerous small air bubbles into the material, some of which may later become trapped directly against the surface of the master model.

Step 11. How to Pour Silicone Without Trapping Bubbles

After mixing, do not pour the entire mixture directly over the master model.

It is much better to place the mold box on a level surface and slowly pour the silicone in a thin stream into one point next to the model.

Allow the material to flow naturally around the object and gradually rise around it.

This allows the silicone to displace air from the relief much more effectively than pouring it randomly over the entire surface.

Do You Need a Vacuum Chamber?

Vacuum degassing is not always necessary for simple, small molds.

With careful, slow mixing and proper pouring, high-quality liquid silicone can fill most standard reliefs successfully.

However, when making complex professional molds with many fine details, vacuum degassing can help remove air from the mixture and reduce the risk of defects.

Step 12. Do Not Try to Heat the Silicone Aggressively

When working with epoxy resin, makers often use heat to remove bubbles. This habit should not automatically be transferred to silicone.

For Pure Mold available from M | Art Studio, the product information states that the material should not be used at temperatures above 30°C.

Therefore, there is no need to heat the pour with a heat gun, place it next to a strong heat source, or try to accelerate curing with extreme heat.

It is much more important to:

• mix the components correctly;
• pour the silicone slowly;
• leave the mold on a level surface;
• maintain stable curing conditions.

Step 13. Leave the Silicone Until Fully Cured

After pouring, do not move or tilt the mold box.

For Pure Mold available on the M | Art Studio website, the specified curing time is approximately 8 hours. After this time, the mold can be removed from the mold box.

Do not try to check the mold too early by pressing on the surface or pulling out the master model.

If the silicone has not yet developed sufficient strength, the mold can be stretched or damaged at this final stage.

Step 14. Disassemble the Mold Box

Once the silicone has fully cured, begin by removing the walls of the mold box.

Do not immediately try to pull the master model through a narrow opening, particularly if it has projections.

Carefully free the silicone from all sides.

If the mold box was assembled from separate panels, it is usually easier to dismantle it piece by piece.

Step 15. Remove the Master Model

Now slowly separate the silicone from the model.

It is better to peel and flex the silicone away, gradually releasing the object, rather than pulling the master model out forcefully.

Be particularly careful around:

• thin projections;
• sharp corners;
• deep relief;
• small decorative details.

If the geometry of the master model was planned correctly, the elasticity of the silicone will allow the object to be released gradually.

After removing it, inspect the inner surface of the new mold carefully.

How to Tell Whether the Mold Is Good Quality

A good silicone mold should:

• fully reproduce the master model;
• have sharp, well-defined detail;
• have no large bubbles on the working surface;
• have no sticky or liquid areas;
• maintain its shape;
• have sufficiently thick walls;
• release easily from the master model;
• have no accidental tears.

Small external irregularities that do not affect the working surface can usually be carefully trimmed after the silicone has fully cured.

Why Are There Bubbles on the Surface of the Mold?

If a bubble is located inside a thick outer wall and does not reach the working surface, it may have no effect on the finished result.

The problem occurs when an air bubble becomes trapped between the silicone and the master model.

Once the model is removed, this area will leave a cavity or defect that will then be reproduced in every casting.

The main causes include:

• mixing too quickly;
• pouring silicone directly over the textured surface;
• a mixture that is too thick;
• a large number of small recesses in the model;
• air trapped in complex geometry.

For highly detailed objects, it is therefore particularly important to pour the silicone slowly and allow it to fill the relief naturally from the bottom upward.

Why Did the Silicone Not Cure?

If sufficient time has passed but the silicone remains soft or liquid, it is important to determine exactly where the problem is occurring.

The Silicone Did Not Cure Throughout the Entire Mass

Possible causes include:

Incorrect component ratio.

Two-component systems require the recommended ratio to be followed accurately.

The components were not mixed thoroughly.

Material may have remained on the walls or bottom of the container without being properly combined with the second component.

The temperature was too low.

Curing of many silicones slows down in cold conditions.

The Silicone Cured, but the Area Next to the Master Model Remained Sticky

In this case, platinum silicone cure inhibition may have occurred.

If the problem appears only on the surface that was in contact with the model, the cause may be an incompatible material, paint, modeling clay, latex, contamination, or a particular type of 3D-printing resin.

This is why a small compatibility test can save a significant quantity of silicone.

Do You Need to Use a Release Agent?

There is no universal rule that says a release agent is always required.

It depends on the material of the master model and the construction of the mold.

Silicone releases quite easily from many smooth, non-porous surfaces.

However, a release agent can be useful:

• with complex geometry;
• on certain porous surfaces after they have been sealed;
• when making multi-part silicone molds;
• when a new layer of silicone will come into contact with already cured silicone.

One particularly important point to remember is that silicone bonds very well to silicone. Therefore, when making two-part molds, a suitable release material is required between the first and second halves.

How to Make a Mold with I-GUM Silicone Putty

For small objects, you do not necessarily need liquid silicone or a mold box.

I-GUM silicone putty works in a different way.

Components A and B are taken at a 1:1 ratio by weight and kneaded thoroughly until a completely uniform mass is obtained. Once mixed, you should begin making the mold immediately because the working time of the material is limited.

There are two possible methods.

First Method

Apply the silicone putty directly to the surface of the master model, carefully pressing the first layer into all the details of the relief.

Second Method

Form a layer of putty on the work surface and press the master model firmly into it.

Once the silicone has cured, remove the object.

This method is particularly useful for:

• small decorative elements;
• textures;
• medallions;
• reliefs;
• impressions;
• vertical surfaces;
• simple molds for which you do not want to build a separate mold box.

Can I-GUM and Liquid Pure Mold Be Used Together?

Yes.

For some complex or large molds, these materials can be used together.

For example, silicone putty can help to:

• quickly create walls or borders;
• seal areas through which liquid silicone could escape;
• create part of the mold construction;
• reduce the amount of liquid silicone required.

The main detailed section can then be poured with liquid Pure Mold.

This combined method can be particularly useful for makers beginning to create their own non-standard molds.

What About Liquid Latex?

Liquid latex is also used for making flexible molds and impressions, but it is important to understand that latex and silicone are different materials that require different working methods.

Latex is typically applied in multiple thin layers, allowing each layer to dry between applications.

Two-component liquid silicone, by contrast, is mixed immediately before use and forms a mold through a chemical curing reaction.

Therefore, if your goal is specifically to create a durable reusable mold quickly by pouring material around a master model, liquid silicone is usually the more straightforward option.

Can You Make a Silicone Mold for Candles?

Yes.

Silicone molds are widely used for making molded candles.

You can create your own master model, make a silicone mold from it, and then pour candle wax into the mold.

However, during the design stage you should already consider:

• how the finished candle will be removed;
• where the wick will run;
• whether technical openings are required;
• whether the mold is flexible enough;
• whether the model contains excessively complex undercuts.

For complex three-dimensional candles, the mold may require a longitudinal cut after the silicone has cured.

Can You Make a Mold for Epoxy Resin?

Yes. This is one of the most common applications for silicone molds.

Pure Mold is suitable for use with epoxy resin and can be used to produce detailed repeat castings.

For transparent or glossy resin pieces, the quality of the surface of the master model is particularly important.

Every scratch or matte area inside the mold will be reproduced on the finished piece.

This is why a good mold begins with a well-prepared original.

Can a Silicone Mold Be Used with NATURESIN?

Yes.

Silicone molds are suitable for acrylic composites, including NATURESIN.

This allows you to make your own molds for:

• trays;
• coasters;
• vases;
• candle holders;
• decorative figurines;
• organizers;
• small interior decor pieces.

When designing a large mold, it is important to consider the weight of the finished piece. Very soft, thin walls may deform under load, so larger molds sometimes require an external rigid support.

Can You Make a Silicone Mold for Food?

It is important not to confuse two separate concepts.

The fact that a silicone uses a platinum catalyst does not automatically mean that the specific product is certified for food contact.

For chocolate, confectionery products, ice, and other food applications, you must use silicone that has the appropriate food-contact certification.

Always check the documentation for the specific material you intend to use.

10 Common Mistakes When Making a Silicone Mold

1. Choosing a Model That Is Too Complicated for Your First Attempt

Start with a simple open mold. This makes it easier to understand the basic process.

2. Failing to Secure the Master Model Properly

A lightweight object may shift or float.

3. Building a Mold Box That Is Not Leak-Proof

Even a small gap can allow a significant amount of silicone to escape.

4. Making the Mold Box Too Large

This leads to unnecessary silicone consumption.

5. Making the Mold Walls Too Thin

They may stretch, turn inside out, and distort future castings.

6. Measuring the Components Inaccurately

Two-component materials require the correct ratio.

7. Mixing Too Quickly

The more vigorously the mixture is whipped, the more air is introduced.

8. Pouring Silicone Directly Over the Relief

It is better to pour slowly into one point and allow the material to flow around the model naturally.

9. Failing to Check Master Model Compatibility with Platinum Silicone

A small preliminary test is particularly important when working with modeling clay, latex, painted surfaces, and certain 3D-printed materials.

10. Removing the Model Too Early

Even if the surface feels firm, the silicone inside may not yet have developed sufficient strength.

What to Do with a New Mold After Making It

After removing the master model, inspect the mold and carefully trim any unnecessary thin edges or excess silicone.

Before the first casting, make sure there is no:

• dust;
• residue from the master model;
• silicone trimmings;
• foreign debris.

The future service life of the mold depends greatly on correct use and storage.

Do not stretch the mold more than necessary, do not pull cast pieces out by thin decorative details, and store the mold without deforming it.

For more information about storage, cleaning, and extending the service life of silicone molds, see our separate article “How to Care for Silicone Molds: Tips That Help Extend Their Service Life”.

Where to Find More Information About Materials

If you are just beginning to work with silicones, epoxy resin, NATURESIN, wax, and other creative materials, we also recommend visiting the M | Art Studio FAQ.

There you can find additional information about materials, their characteristics, applications, and basic working principles.

Ready-Made Mold or DIY Silicone Mold: Which Should You Choose?

These two options do not compete with one another.

If a good-quality ready-made mold is available in the size and design you need, buying it saves time and allows you to begin casting immediately.

Making your own mold becomes particularly useful when you need:

• an individual design;
• a non-standard size;
• your own master model;
• a unique relief;
• a mold that is not commercially available;
• a series of original pieces.

After making several simple molds, it becomes much easier to understand mold geometry, plan the position of the master model, and move on to more complex projects.

The Most Important Point: A Good Silicone Mold Begins Long Before the Pour

The actual process of mixing and pouring silicone is only a relatively small part of the work.

The quality of the mold depends primarily on preparation:

the right master model + well-planned geometry + a leak-proof mold box + an accurate component ratio + careful mixing and pouring.

For your first project, avoid choosing a complicated three-dimensional object with numerous undercuts.

Start with a simple shape, carefully prepare the surface and mold box, weigh the components accurately, and do not rush the mixing process.

Once you understand the basic technique, you can move on to two-part molds, larger molds, combined use of liquid silicone and I-GUM, and creating your own professional molds for epoxy resin, NATURESIN, wax, and other materials.