[QUOTE=Sean Factotum]
Easy to solve.
Move the display close to the register.
Give whoever mans the register a bunch of pads.
When they see someone using the display as a writing surface, the person at the register throws a handful of pads at the scribbler.
[/QUOTE]
Even better if the pad is glued to a brick!
[QUOTE=SP2263]
Too bad you can’t make black labels with white print.
[/QUOTE]
Now* that’s* a good idea! And of course you can, with any word processing or cheap art program.
[QUOTE=Zabali_Clawbane]
Would it be possible to have some kind of paper flap in place over the labels, that people could mark on, and not the label? A paper flap could be raised to get the price, and easily replaced once it was too used. 
[/QUOTE]
These people would lift the flap, scribble on the price tag, and then be on their merry way.
Trust me.
[QUOTE=gotpasswords]
Could be worse. You could be selling spray paint and dealing with cretins that don’t understand the “cap color is the paint color” concept and have to be sure that green paint really is green, using the shelves or the floor as the test spot.
[/QUOTE]
In defense of these assholes…but just sorta…I’ve purchased paint that someone had switched the caps on, just to be a comedian. However, I wouldn’t spray it on something to test it. I’d just bring it back if I got a switched one.
[QUOTE=Baker]
That’s a good one! It reminds me of being in the girl’s bathroom in a bar I went to, while in college. On the wall there was the painting ofa man, wearing only a loincloth. Said loincloth was on a hinge. It said “DO NOT LIFT THIS LOINCLOTH!!!”
Of course I lifted the loincloth, and was rewarded with a loud buzzer and a flashing light when I left the room, proclaiming to all that I’d looked.
I remember hearing it earlier, not knowing what was going on or why folks laughed. And none of the other women told us about it, because they didn’t want to be the only one caught!
[/QUOTE]
I’d be tempted to go back in there and jam something in the hinge so it would seem as if some lady was in there looking and looking and looking… Of course, there was probably nothing to see. 
The OP reminds me of how you see so many cosmetic displays in department stores slathered all over with lipstick or nail polish or what-have-you. barf
You said the display is acrylic. Is it clear?
Is it possible to stick the labels on the inside of the displays so that it shows through.
[QUOTE=Hunter Hawk]
Or use those little plastic label holders that hang freely?
[/QUOTE]
I second this. We use these at work: Plastic Badge Holders
You slip your tag inside it and they’re pretty hard to mark on, save for maybe with a Sharpie and when I tried it just now I was able to wipe it off with a tissue. Even if someone does manage to ruin one, they cost less than $5 for a pack of 12.
I use poster putty to stick them to items since the putty won’t leave a mark, but you could probably just use double sided tape.
Then you could just print your pen labels up on regular paper and make them as pretty as you like. 
[QUOTE=Zabali_Clawbane]
Would it be possible to have some kind of paper flap in place over the labels, that people could mark on, and not the label? A paper flap could be raised to get the price, and easily replaced once it was too used.
[/QUOTE]
Heyyyy…that could be an idea. Maybe a translucent vellum or something…that’s something to think about. Thanks!
So people have been swinging dead lemurs at the labels? That sucks, man.
How 'bout using a label maker. They’re cheap these days and the strips that come out of them already have the laminated glossy feel (you wouldn’t be able to write on them easily) and they have adhesive on the back.
[QUOTE=gigi]
So people have been swinging dead lemurs at the labels? That sucks, man.
[/QUOTE]
Seriously. It’s not even sporting, man - how can the lemur grab at the pens and fling them into Aisle 4 if it’s dead? 
Perhaps they are un-dead lemurs.