lasti-Bat was designed by studio potters to be a versatile, long-lasting, high-quality bat that is virtually indestructible! Made of 1/4" to 3/8" thick, very rigid, high impact plastic, they will provide continuous use, will not splinter, delaminate, swell or shrink. They are easy to clean and are impervious to water and most chemicals. Plasti-bats drilled with pin holes have one oblong hole for a better fit on your Amaco or Brent wheel. The holes will remain just as drilled and will not become oversized with use. The 8" to 18" bats are 1/4" thick and the 20" bats are 3/8" thick. We recommend storing Plasti-bat plastic bats in a slotted rack such as the Amaco Batmobile or stacked on a FLAT surface to prevent warping. When stacking Plasti-bat plastic bats, be sure they are clean prior to stacking. Even the slightest obstruction can cause the bats to warp.