Description Portal 2 Aperture sign
Basic rules of conduct are important. Very important. This applies not only to chemistry labs, the kitchen (not to be confused with the former) or your own room, but also - or above all - to the Aperture Laboratories from Valve's game Portal.
Fortunately, there are handy signs everywhere so that the lucky test subjects can't claim that they "didn't know any better".
Aperture Science is particularly talented at formulating meaningful and absolutely unambiguous rules:
"Don't leave your stuff here"
"Do not loiter here for more than twenty minutes"
"Do not touch the glass"
and
"Wear a shirt and shoes at all times"
"Move quickly through the test track"
"Don't forget not to touch the glass"
The glass in particular seems somehow... of importance. Fortunately, this approximately 14.2 x 28 cm sign is made of sheet metal and we are therefore allowed not to touch it and to hang it up wherever a few firm rules are needed.