Cake mix will give you a very smooth slime. Pancake mix will give you a thicker slime that can also "rise" with air bubbles if it sits too long. Brownie mix will be.... You know.... Chocolate slime, like brownies. Never tried cookie mix.
Cake batter has great consistency and colors well, washes off easily, and is probably the best all-around substance on this list. Pancake mix has a lot of baking powder in it, and so it doesn't taste very pleasant. Cookie mix will be very thick, nearly the consistency of bread dough, and therefore largely unsuitable for WAM. Brownie mix is the most decadent of these, I love its thickness, its richness, and its taste and smell. If I'm getting messy with a girl, it's near the top of the list.
Ariel said: For sure that brownie batter is the bomb dot com lol It's very thick and dense. Much heavier than the others. Silkier. Richer. The smell and taste so divine. It takes a lot of the powder to make a bowl of batter. Much more than it takes of the cake mix. Can anyone explain that? Is it the rise?