Custom Flat Work In addition to 3/8” tub and shower wall materials, 3/4” material can also be cast in a smooth finish up to 84” by 120”, and in a slate finish up to 60” by 144”. Some examples are: L-shape tops, corner vanity tops, bar tops, tub decks, windowsills, thresholds, shelving, hearths and mantles – whatever the need may be. These products can be cast and are only limited in size by the dimensions of our molds.