A good source for info is Olson blades they have a chart that covers most blade types and recommended uses. All blades are similar skip tooth is a skip tooth, spiral is spiral, size is relatively the same so if you want reverse blades in a size 3 All brands will be very close. All old scrollers have favorite blades and favorite brands. Thin wood needs smaller blades 1,3 thicker wood 5,7,9 very thick 9,12. Good luck. I hope this doesn't confuse you try different brands then pick the best for you. Most blades are less than $4 a dozen.