Do you use Shrink Film in your classroom? I'm going to do a project this coming year, and was testing out time/challenges with my daughter. I'm concerned about it going too dark if everything was done in Sharpie....so we outlined with Sharpie & colored it in with colored pencils. This seemed to work out great. I did not rough up the surface first because it had a mat finish already. I know some products it is best to go over it a little with a fine grit sandpaper so the color stays put!
My video ended sooner than expected because storage was full!
(I really need to delete some of my 2000+ photos!)
I cut a sheet into quarters to start. After the images were drawn I cut around each....leaving enough space at the top to hole punch so we could make them into necklaces. You may need to make the hole larger than a standard hole punch will create depending on what you are using to string the necklace with. You may need to do some experimenting to get it just right!
If your oven is hot...it should take around 2 minutes to shrink & flatten back out. If it doesn't flatten completely in the oven....as you pull it out push down the edges(that should do it!). I only place two to four on the tagboard(it is a thick non-corrugated cardboard kind of material). That way they won't touch and possibly stick together(it has happened before...but not often). My toaster oven has to racks...so I can do 8 at a time(if you are thinking about how long it will take you to complete a class).
We used SPARKLE MOD PODGE to coat it with once it could down. Don't rub too hard when you brush on the clear coat of your choosing...it might cause the color to smear.
(I used waxed string to make my daughter's necklace...I really like it!! Easy to use..slides through the holes...easy to tie....affordable.)