>> Did you see the added hint I wrote in the comments section?
Was that point #11, a little ballpoint ink stays in the indentation for a little while?
The only paint pens I found had much too wide a line for my taste, even the ones called "fine point". Also, when I tried using paint pens to re-mark keys on my PC keyboard, it flaked off in less than a day. But those are pretty glossy plastic and I do hammer on them pretty hard.
I always thought that the blinds I'm using now have a very slightly matte or roughened surface that takes pencil well, especially a wide lead. They were old and dirty when I got them. So I washed them with Comet cleanser (abrasive) and then put them through a dishwasher. That may have made the surface more receptive to penc il,l or the old plastic might have become porous with age. I found a spare set of b linds for when these run out, and it seems to have a very c lean glossy surface. Maybe I should test it out!
I think that embossed aluminium has to be the longest-lasting label. I think they've found undissolved aluminum cans that had been sitting outdoors ever since aluminum cans were invented! If acid rain attacks them at all, it sure doesn't do it fast enough to detect.
.
