Low Fire, Stoneware or Porcelain Slip: Which Should You Choose?

Every one of our slip casting kits now lets you pick your slip: Low Fire, Stoneware or Porcelain. All three pour the same way into the same plaster mold, so the real question is how hot your kiln gets and what you want the finished piece to do. Here is a simple way to decide.

Start with your kiln

This is the most important part. Every clay body has a firing range, and your kiln has to reach it.

• Low Fire slip fires at cone 06 to 04. Almost every hobby and studio kiln can do this, including most small test kilns.
• Stoneware and porcelain slip fire at cone 5 to 6. You need a kiln that is rated to reach that range and the wiring and elements to get there.

If you are not sure what your kiln can do, check the plate on the side of the kiln or the manual. If it says cone 6 or higher, you can use any of the three. If it tops out around cone 04 or 1, stick with low fire. Our guide on buying your first kiln covers this in more detail.

Low Fire: bright white and easy

Low fire white slip dries and fires to a clean, bright white. It is the easiest place to start and works great for:

• Ornaments, figurines and holiday decor
• Pieces you plan to paint with underglaze or bright low fire glazes
• Projects for kids, classes or parties where you want quick, simple firings

Low fire pieces are a little more porous than stoneware or porcelain, so they are best for decorative work or pieces that get a full coat of glaze. Pair them with our low fire glazes for bold color.

Stoneware: strong for everyday pieces

Stoneware slip fires at cone 5 to 6 to a tough, dense body with a warm white color. It is our pick for anything that gets used and washed a lot:

• Mugs, cups and tumblers like our ring cup kit
• Planters and pet bowls
• Soap dishes and kitchen pieces

Stoneware works with midrange glazes, which give you a huge range of reactive, speckled and glossy looks.

Porcelain: smooth and refined

Porcelain slip also fires at cone 5 to 6, but it gives you the smoothest, brightest surface of the three. When cast thin, it can even let a little light through. It is a great fit for:

• Delicate ornaments and jars like our honeycomb jar kit
• Pieces where crisp detail really matters
• Clear or celadon glazes that show off the white body underneath

Porcelain is a little less forgiving while drying, so let pieces dry slowly and evenly to avoid warping or cracks.

Quick comparison

• Kiln needed: Low Fire works in almost any kiln. Stoneware and porcelain need cone 5 to 6.
• Color: Low Fire is bright white, stoneware is warm white, porcelain is the brightest and smoothest.
• Strength: Stoneware and porcelain fire stronger and less porous than low fire.
• Best for: Low Fire for decor and painting, stoneware for everyday use, porcelain for fine detail.

Do not mix firing ranges

Whatever slip you pick, match your glazes to it. A low fire glaze on a cone 6 piece will usually run or burn off, and a cone 6 glaze on a low fire piece will not mature. Our post on low fire vs high fire glazes explains why.

Ready to pick your slip?

Browse our slip casting kits and choose Low Fire, Stoneware or Porcelain on any kit. Want to learn the basics first? Read how slip casting and plaster molds work.