(Q) What kid of sandpaper should I use with these blocks?
(A) Use 31370 to 31377 Adhesive-Backed Sandpaper, 2-3/4" wide (82-3/4-ft.-long rolls or 16-1/2"-long sheets, in a variety of grits)

(Q) Should I use guide coat?
(A) Applying guide coat will show you the surface's high and low points as you sand. It will make it easier to identify where you need to take down high spots or add filler to low spots.

Five 2-5/8"-wide, 1/2"-thick Block Sanders:
19855 1/3-Block, 5-1/2" long
19856 2/3-Block, 11" long
19857 Full-Size Block, 16" long
19861 Long Block, 24" long
19862 Marine Block, 30" long

Instructional DVD produced by Steve's Auto Restorations

Always wear eye, skin and respiratory protection when using Dura-Block Sanding Blocks or other sanders. Make sure you are in a well-ventilated area and follow the safety precautions on paint and filler labels. 31370 to 31377 Adhesive-Backed Sandpaper, 2-3/4" wide (82-3/4-ft.-long rolls or 16-1/2"-long sheets, in a variety of grits)
12416Z Eastwood Guide Coat, Black
12417Z Eastwood Guide Coat, Tan
50758Z Finishing Glaze
50242ZP Eastwood Epoxy Primer 1:1, Quart
50243ZP Eastwood Epoxy Primer Catalyst 1:1, Quart
50771Z Spray Max 2K Aerosol Epoxy Primer, Aerosol

wet & dry sanding, final finishing before painting removal of guide coat, smoothing of fillers, bondo etc