Hi Mona,
I use the 'waterproof' address labels to label my daylilies and they work great. But, you do need to use a laser printer, not an inkjet. At least that's been my experience..... I too, use the plastic mini blinds with pencil for my seedlings--I got mine for really cheap at a garage sale. My main problem with them is being able to see what the cross is when I go to take a photo. So, last year I bought some pvc conduit and cut it into 2' sections and stuck a label on it--worked a little better. I just did this at the beginning of each new cross. It would probably work great if I didn't have my seedlings so close together that it's still hard to tell which row a bloom belongs to :~).
Ann