Materials: Ruler Pencil 3" (7.5-cm)-diameter mailing tube Craft knife 35 oz (1 kg) white DAS air-dry clay 2 (1 x 15 x 0.25" [2.5 x 38 x 0.6–cm]) lengths of wood Roller Damp sponge Round metal carving tool Parchment paper Flat blending tool (optional) 3.5" (9-cm) circle cookie cutter Medium-grain sandpaper
Measure and mark 8 inches (20 cm) from one end of the mailing tube. Using a craft knife, cut the tube into two pieces at that point. I find it helps to lightly score the line around the tube first to keep it straight.
Place your block of clay between the lengths of wood on a nonstick surface. Roll out the clay. Keep turning the clay every five to ten rolls to make sure you end up with a piece that is almost a square.
Measure and mark 9.5 x 8 inches (24 x 20 cm) in the piece of clay, ensuring all corners fit onto the piece of the clay you have rolled. Use a craft knife and the straight side of the wood to cut along each side. Remove the excess clay. Using water and a sponge, smooth over the surface and edges of the rolled-out clay.
Gently score a line about 0.5 inch (1 cm) inside from the edge, along both of the 8-inch (20-cm) sides of clay. You’ll need to smooth this line out later; the lighter you press, the easier it will be.
Place a piece of wood 0.75 inch (2 cm) from the edge of the longer side. Use this piece of wood as a guide when you cut the clay with the carving tool. Gently line up the end of the carving tool with your scored line in the clay. Press the tip into the clay while holding the tool at a 45-degree angle. Once the tool is submerged into the clay at its widest part, run it along the wood to the opposite side. Just before you reach the other end, take the tool out and place the tip of the second line holding the tool so it is at a 45-degree angle again— this time facing the opposite direction. Repeat the action of gently pressing the tool into the clay until it meets the groove you just made.
Remove the excess clay and move the wood down 0.75 inch (2 cm). Repeat the action with the carver tool to create another groove. Continue to make the grooves along the surface until you reach the other end of the clay.
Wet the sponge with a little water and smooth over the surface of the clay. Use your finger in each groove to smooth over any cracks or rough areas.
Carefully lift the clay onto a piece of parchment paper and fold the parchment paper over around an inch (2.5 cm) from one of the shorter ends. Lift this end onto the mailing tube. Pull back the parchment paper as you wrap the clay around the tube, holding it in place with your other hand.
When the clay wraps around the entire tube, wet the edges where they meet and gently blend them together with your fingers or a flat blending tool.
Leave the clay to dry for 24 hours. It will be dry on the outside; if the clay still has darker patches, leave it to dry until the outside looks bright white. Very gently push the mailing tube out of the center. If the clay begins to move out of shape, stop and leave it to dry for another 24 hours.
Roll out the remaining clay between the lengths of wood. Cut a circle with the cookie cutter. Wet and score just inside the edge of one side of the circle. Place this on the bottom of the vase and blend the outer edge of the clay over the join to create a seamless join.
Take small pieces of clay, wet them and blend them to the inside of the vase along the join to hide the seam.
Leave it for 24 hours to dry, then sand it smooth using a medium-grain sandpaper.
Excerpted with permission from <a target="_blank" href="https://www.amazon.com/gp/product/164567150X/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=164567150X&linkCode=as2&tag=craftfocom-20&linkId=9d01cd66f851b50ae301da5eddd6da83">Easy Homemade Pottery: Make Your Own Stylish Decor Using Polymer and Air-Dry Clay</a>.