I use strips from window blinds too -- but only for temp markers for new plants. Started doing this last year -- my permanent markers are too expensive to make and throw away the marker plates for Irises that don't make it.
However -- I do make regular Brothers tape labels for the blinds strips. No chance of them fading.
My only complaint about the blinds strips is that they can bend very easily -- and once creased, do not want to stand up straight again. We have heavy clay soil here, so sometimes it can be hard to push a blinds strip into it, and that's how they get bent to begin with. But -- these are temporary markers anyway -- so no big deal.
