In a well-ventilated area, pour 1 lb bag of dry slip mix into a bowl. Add 1 1/2 cups water and mix with a whisk or immersion blender until smooth. The slip should be a thick yogurt-like consistency. Press slip through a sieve or strainer to eliminate any lumps in the mixture. Slip will thicken during the first day it is mixed and more water can be added to return it to its original consistency. We usually get good results using this slip thickness, but you may wish to thin it slightly with additional water. Experiment to find what works best for your particular application.