Spurred by Jason’s comment on the laser test paper trials, I engraved some Tyvek:
You probably can’t see the “Test!” engraved below the blue logo, as it just changed the texture of the envelope without producing a visible mark.
The upper-right “Test!” ran at 10% (of 60 W) at 400 mm/s, with the others at 15% and 20%. The results suggest that it’s possible to remove ink and leave a visible mark, but it’s neither pretty nor dependable.
Somebody’s gotta have a weather-stable, super-flexy, dual-color, laserable material, but so far it’s hidden below my horizon.
The Smell of Molten Projects in the Morning 
I have about four ideas a day. Occasionally, one of them is even a good idea. Not this time. On the plus side, it looks like this stuff is really easy to cut if you need something with Tyvek’s other properties.
Four ideas a day puts you in the top 1%, I’d say. :grin:
Stuff does cut like butter, so it’s gotta come in handy for something.
Seems like this might be the answer. You’d probably want to stick it to a sheet of mylar before cutting.
https://shop.troteclaser.com/en-US/category/sheet-material/laserable-plastics/trolase-foil/0ZG4I000000GmlDWAS
Apparently Trotec has reshuffled their online shop, discarded my previous ID, and changed the Terms of Service to exclude retail = non-business customers. Maybe I misunderstand what happened, but a first glance isn’t encouraging.