There is a very simple, clean and quick solution to attach signs to smooth surfaces: suction cups. So you can attach suction-cup signs to doors or whiteboards without leaving any residue and without drilling. Simply press on and you're done.
The signs can be used in many ways. Suction cup signs are popular for flexible signposting of rooms for training courses or for use as information signs when, for example, rooms at teaching institutions are occupied. A practical sign with suction cups can also be used at events, trade fairs or in sales. Here you can have suction cup signs printed at a low price.