Skim milk, crusts, middlings, bits of doughnuts, wheat cakes with drops of maple syrup sticking to them, potato skins, leftover custard pudding with raisins, and bits of Shredded wheat.

It is a painting technique where a paint brush is relatively dry but still holds paint.

Partial cleaning: First, use neutral cleanser, for example, dish cleanser, with soft cloth to wipe the dirt. After that, wipe again with dry soft cloth, which can prevent to leave water stains.