Mold walls out of wed clay?
What are the downsides if any, of making mold walls out of wed clay as opposed to white clay. I'm asking because it's what I have at the moment. Thanks!
That depends on what material your sculpt is, and what type of mold material you plan on using.
You want the clay for your mold walls to be softer than the clay of your sculpt, so you are less likely to damage your mold while building the walls.
You also want a clay that is not going to cause issues with your mold making materials. For example, urethane resins react poorly to the water in WED clay (or white clay)
White clay (EM-210) is great for making stone molds, and WED clay would work as an alternative in a pinch.
Another common mold wall clay is "klean klay" and its various alternatives (like Van Aken Protolina) and is great when making fiberglass or silicone molds.