Depending on the technique used by the artist, acrylic can produce results that are like oil or watercolour ... and painting knives are useful for mixing paints together into a consistent colour.

It's made from a drying oil, like flaxseed, and pigment sometimes with fillers and thickeners added to the mix. When mixed and crushed, these ingredients bind and thicken to form a permanent paint.

Depending on the technique used by the artist, acrylic can produce results that are like oil or watercolour ... and painting knives are useful for mixing paints together into a consistent colour.

Oil and water do not mix so the solvent base in the oil paint forms a barrier that won't let the latex or acrylic paint bond to it. This is what causes the paint to peel or flake off after some time.