Crock pots can  range from about 1.5 qts to over 8 qts - so what is the best size? It will kind of depend on how much encausutic medium you intend to make! But, I recommend the mid size, anywhere from 5-7 quarts will be the most useful - which are good for batches of approximately 12 cupcake size cakes of encaustic medium. Look for smaller or bigger sizes if you intend to make very small batches, or very large batches of wax, respectivey.