This is a test of commonsense. Complete the next sentence:

How to apply decals
Choose a flat surface to put your decal on.
You can put your decal on a wall, glass window, painted wood, the outside of a vehicle, or another non-porous flat surface. Avoid porous surfaces made out of things like brick, cement, and leather, or your decal may not stick properly.
Avoid applying your decal in extreme temperatures. Put your decal on your chosen surface when it's between 50-90 f (10-32 c) outside or in the room you're applying it in.