I use the Olfa the you have to squeeze the handle on to get the blade to show and it retracts when you let go....saves on blades.....and only use the Olfa blades seem to be sharper....I oil my blade once in awhile and that seems to make it last longer....maybe I'm crazy but if it works wooo hoooo......:-).......someone suggested running blade threw foil....sharpened the blade.....:-) .....haven't tried that one but will give it a go....:-)