What Paper Clay Is Best For Molds?

What is Paper Clay?

Paper clay is a modeling material made from clay and cellulose fiber, typically paper pulp. The cellulose fiber acts as a reinforcing material to give the clay more strength and flexibility compared to regular clay. Some key features of paper clay include:

– Paper clay has high plasticity and does not need armatures for support like regular clay may require. It can be sculpted thinly without risk of cracking or breaking while drying.

– When dry, paper clay has more strength and stiffness than air dry clays, making it suitable for more durable sculptures and usable molds.

– It shrinks minimally when drying, usually around 5-8%. This makes dimensional accuracy easier to control compared to other clays that shrink more.

– Paper clay is lightweight compared to ceramic clay or polymer clay. Finished sculptures are easier to move and ship.

– It can be sanded, carved, drilled, and finished much like wood when dry. Many types of paint, glaze, and other finishes adhere well to paper clay.

– Paper clay is non-toxic and environmentally friendly. Most types can be disposed of normally or even recycled.

Some limitations of paper clay include potential breakage if very thinly sculpted, susceptibility to moisture which can weaken dried sculptures, and less durability for outdoor use than ceramic clays. Proper sealing and protective finishes help minimize these weaknesses.

Overall, paper clay combines the workability of clay with the strength of paper, making it suitable for detailed sculpting and mold making needing durability and dimensional stability.

[https://www.dolliehsanctuary.com/sanctuary/viewtopic.php?f=13&t=6415]

Popular Types of Paper Clay

There are a few main types of paper clay that are commonly used for mold making and other clay projects. These include:

Cellulose Paper Clay – Cellulose paper clay is made from cellulose fiber, often derived from wood pulp or cotton. It typically contains paper fibers and an acrylic polymer binder. Cellulose paper clay is lightweight, strong, and inexpensive. Popular cellulose clay brands include Creative Paperclay and Activa Paperclay. (source1)

Abaca Paper Clay – Abaca paper clay is made from abaca plant fibers, which are very strong and durable. Abaca paper clay has a coarse, fibrous texture and is ideal for sculpting and modeling as it holds fine detail well. It’s more lightweight than cellulose paper clay. Popular brands are Paperclay and Hearty Clay. (source2)

Mulberry Paper Clay – Mulberry paper clay contains mulberry bark fibers and tends to be very smooth with a fine texture. It’s extremely strong and flexible. Mulberry paper clay is often used for delicate sculpting and detailed molds. A popular brand is Paper Magic Clay.

Non-Wood Paper Clay – Some paper clay contains no wood pulp at all. Non-wood options include clay with 100% cotton linters or hemp fiber. These offer high durability and strength. Two popular non-wood brands are Aardvark Clay and Fibreclay.

Factors to Consider

When selecting the best paper clay for mold making, there are several key factors to take into account:

Strength and Durability

Paper clay contains cellulose fibers from paper, which gives it added strength and durability compared to regular clay. However, some paper clay blends are stronger than others. The higher the ratio of paper pulp to clay, generally the stronger the paper clay. Stronger paper clay is less prone to cracking and holds fine detail better when used for molds. According to ceramicartsnetwork.org, higher-fire clays like stoneware tend to make the strongest paper clay.

Flexibility

Flexibility refers to how easily the paper clay can bend without cracking. More flexible paper clay works better for making molds of objects with complex shapes and undercuts. The clay composition affects flexibility. As mentioned on susiebenes.com, natural earthen clays tend to be more flexible than purified clay.

Moldability

Moldability refers to how easy the paper clay is to shape and sculpt. Paper clay made from smooth, plastic clay blends tends to have superior moldability compared to coarser clay bodies. The recipe also impacts moldability – higher paper pulp ratios can make paper clay more difficult to manipulate.

Drying Time

Depending on the project, you may want paper clay that air dries quickly or more slowly. Thinner layers dry faster. Denser paper clay compositions and clay with higher grog or filler contents tend to dry slower. Faster drying allows faster mold making but can cause cracking if dried too quickly.

Shrinkage

Like regular clay, paper clay shrinks slightly during drying. Less shrinkage is ideal for mold making so the finished mold holds accuracy. Paper clay shrinks less than regular clay. Higher paper pulp ratios result in less shrinkage.

Cost

Paper clay ingredients – especially the paper pulp – can be expensive. However, opting for a cheaper paper clay could mean sacrificing mold quality and performance. Evaluate the cost against the other factors like strength and flexibility to choose the most appropriate paper clay for your budget and needs.

Best Paper Clay for Mold Making

When selecting the best paper clay for mold making, there are three main types to consider: cellulose, abaca, and mulberry paper clays.

Cellulose paper clay is made from recycled paper and cellulose fiber. It is an excellent choice for molds because it is smooth, flexible, and durable. Cellulose paper clay can capture very fine detail, making it great for intricate molds. It also releases easily from molds without sticking or tearing. Common brands of cellulose paper clay include Creative Paperclay and Papermagic.

Abaca paper clay contains abaca plant fibers, giving it strength and flexibility. Abaca paper clay has high absorbency so it can pick up textures well. It can be used to create detailed, reusable molds. A popular abaca paper clay is Makins Clay. One downside is that it may shrink slightly during drying.

Mulberry paper clay is made from the bark fibers of the mulberry plant. It has a soft, silk-like texture that is easy to sculpt and shape. Mulberry paper clay is able to pick up very subtle textures and details. It also has minimal shrinkage. A well-known mulberry paper clay brand is Joviat Papier Maché. One potential drawback is that it can be prone to tearing if handled too roughly before fully cured.

For the highest quality reusable molds, cellulose or mulberry paper clays are typically the top choices. Abaca paper clay is also excellent, but may require a release agent for complex molds. When working with any paper clay, be sure to follow the manufacturer’s instructions closely.

Tips for Using Paper Clay for Molds

When using paper clay for molds, there are some tips to follow for best results:

Apply a mold release agent like vegetable oil to the mold before adding the paper clay. This will help prevent the paper clay from sticking and make demolding easier (Source: https://www.youtube.com/watch?v=HtNtmU_7LtE).

Allow adequate drying time before demolding. Paper clay molds need to dry thoroughly to harden and properly set, which can take 24-48 hours. Rushing the drying may cause cracks or make demolding difficult (Source: https://www.thicketworks.com/paper-clay-casting-technique/).

Store paper clay molds properly after drying. Keep them in a cool, dry place out of direct sunlight. Avoid moisture exposure which can soften the clay. With proper storage, the molds can be reused multiple times (Source: https://www.youtube.com/watch?v=HtNtmU_7LtE).

Consider the desired surface texture for the finished cast pieces. Pressing into the paper clay can create texture. Smooth molds will give smooth casts. Decide on the texture needed for the application (Source: https://www.thicketworks.com/paper-clay-casting-technique/).

Advantages of Paper Clay Molds

Paper clay molds offer several key advantages that make them a popular choice among artists and crafters.

One of the biggest advantages of paper clay molds is their durability. Paper clay is often reinforced with cellulose fibers or pulped paper, giving it extra strength and flexibility compared to regular clay. Properly dried and fired paper clay molds can be reused multiple times without cracking or deforming.¹

Another advantage is that paper clay molds are flexible for demolding. The added paper content prevents molds from becoming too brittle. This allows castings to be removed from detailed or complicated molds without damage. Paper clay also holds fine detail well for producing intricate castings.

Overall, the durability, reusability, flexible removal, and ability to capture detail make paper clay an exceptional material for making reusable molds in ceramics, jewelry, sculpture, and other crafts.

Potential Drawbacks of Paper Clay for Molds

While paper clay offers many benefits for mold making, there are some potential drawbacks to be aware of:

Shrinkage – Like other polymer clays, paper clay shrinks slightly during the drying and firing process. The amount of shrinkage depends on the specific type and brand of paper clay. Factoring in shrinkage is important when making molds so that the cast pieces end up the intended size.

Longer drying time – Paper clay takes longer to dry fully compared to products like plaster. Extra drying time may be needed before casting into a paper clay mold. Rushing the process risks cracks. Taking measures to accelerate drying can help offset this drawback.

Heavier than plaster – The natural fibers added to paper clay make it heavier than a traditional plaster mold. This may limit options for mounting and require extra structural support. The weight also makes paper clay molds more difficult to transport.

Caring for Paper Clay Molds

Proper storage and handling are important for preserving paper clay molds. Here are some tips:

Store paper clay molds in a cool, dry place away from extreme temperatures. Fluctuations in temperature and humidity can cause the molds to warp or crack over time. Avoid storing molds in an uninsulated attic, garage, or shed where temperatures swing widely.

Wrap molds carefully before storing to prevent accidental nicks and dings. Bubble wrap, tissue paper, or soft rags work well. Hard impacts can distort the mold shape. Handle with care when removing from storage as well.

Do not stack heavy objects on top of stored molds as the weight could deform them. Shelving molds vertically helps save space while minimizing the risk of damage.

When using paper clay molds, let them fully dry before attempting to remove castings. Forcing pieces out before the clay has dried can tear or warp the mold. If pieces stick, carefully wedge a blunt tool to gently ease them out.

Check molds periodically for any tears or holes and repair them promptly with additional paper clay before the damage worsens. This helps maintain mold integrity and extend its useful life.

With proper care, paper clay molds can be used for dozens or even hundreds of castings before needing replacement. Handle them with care and they’ll maintain their shape for as long as possible.

Troubleshooting Paper Clay Molds

Here are some common issues that can arise when using paper clay for molds and how to avoid them:

Cracking

Paper clay can become brittle and prone to cracking as it dries. To prevent cracking:[1]

• Avoid letting paper clay dry too quickly. Keep it covered or wrapped in plastic when not working to slow moisture loss.
• Add a small amount of vegetable oil or glycerin to help keep paper clay flexible as it dries.
• Avoid overly thick or large sections of clay, which take longer to dry evenly.

Distortion

If paper clay dries unevenly, it can warp or distort the mold shape. To prevent distortion:[2]

• Dry paper clay slowly and evenly to prevent moisture differences.
• Avoid placing thick clay over thinner sections.
• Consider using an armature for support if making a large mold.

Loss of Detail

Fine details can be lost as paper clay shrinks slightly when drying. To maintain crisp detail:[3]

• Use well-conditioned clay and avoid reworking excessively.
• Allow to dry thoroughly before removing from mold.
• Gently sand any rough edges if needed after drying.

Properly caring for paper clay molds during drying and storage can help avoid many issues. Patience is key throughout the process.

[1] https://community.ceramicartsdaily.org/topic/335-mold-in-paperclay/
[2] https://community.ceramicartsdaily.org/topic/335-mold-in-paperclay/

[3] https://community.ceramicartsdaily.org/topic/335-mold-in-paperclay/

Summary

When it comes to the best paper clay for molds, Polymer Clay Original and Creative Paperclay are top choices due to their smooth texture and ability to pick up fine detail. Both clays can be used to make flexible molds that won’t crack or break, allowing you to reuse them.

The key advantages of using paper clay for molds are that it’s inexpensive, lightweight, and easy to work with. Paper clay molds don’t require high baking temperatures like polymer clay molds, making the process simpler. Just be sure to let paper clay molds dry fully for 24-48 hours before using them.

For optimal results, choose a smooth paper clay consistency, avoid air bubbles when conditioning the clay, and don’t make the mold too thick. Properly storing and caring for paper clay molds will help them last through many uses. With the right techniques, paper clay can be an accessible, adaptable material for crafting reusable molds.