Layer Up! Making Digital Art with Layers

Imagine you have three sheets of clear plastic. On the bottom sheet you draw a blue sky. On the middle sheet you draw a tree. On the top sheet you draw a bird. Now stack them up — you can see a complete picture! If you only want to change the bird, you just swap the top sheet. The sky and tree stay exactly the same. Digital artists use the same idea inside their art programs. This is called working with layers.