Just use the narrowest saw blade you can get. I've got a 2.6mm on the table saw. Angle the groove slightly so the Polaroid is at a slight angle. Being a tad slack won't hurt one bit. Don't worry about faffing around trying to stop the groove. Smash a long length through the table saw, sand it up, then chop to 100mm lengths. Sand up the ends and splash on something that'll bring the grain out.
Coley
Coley