Enjoy soap making?  Our soap molds are constructed of sturdy 0.5 inch thick walled High Density Polyethylene plastic (HDPE). No liner is needed for cold process (lye based) soap making. We recommend that the consistency of your mix prior to pouring be similar to that of a pudding mix. When pouring the product you can see the outline or swirl of the freshly poured product on top of the mix for a moment before it becomes a smooth part of the mix itself.  A mix thinner than this may promote leakage of product and would require a liner.  A small 3" drywall knife is often pushed down between the molded loaf of soap and the mold walls prior to dismantling the walls for loaf removal. Liner may be needed for other applications. Each mold makes 16 4.5 oz. bars that measure 3.5” wide x 2.5” tall x 1” thick. Taller bars can be made if desired as the interior walls of the mold are 3.25” tall. Interior dimensions of each mold are 16.375” long, 3.5” wide, 3.25” tall. Exterior dimensions of each mold – 19.0” long, 4.5” wide, 4.5” tall.