Bone, Teflon, or wood? A note on folders
A folder is the first tool most binders buy and the one they hold most often. It creases folds, rubs down pasted paper, and turns in the corners of book cloth. I own three, and they are not interchangeable.
Bone
Traditional and pleasant to hold. It gives a crisp, sharp crease, but it will leave a shine on dark papers and cloth if you rub directly on them. I use a scrap sheet between the folder and the work.
Teflon
Slightly soft, and it does not burnish. This is the one I use on covering materials and anything with a matte finish. It is also the most expensive, and worth it.
Wood
Mine is a flat piece of hardwood I shaped myself. It is good for large, gentle pressing across a pasted surface, where a narrow folder would leave lines.
If you only buy one, buy Teflon. If you already have a bone folder, keep a sheet of glassine nearby and it will serve you well.