RE: x acto users beware
I guess I am dating myself as well because I too remember using the double edge blades. Un fortunately, we had less money and did not have the "nice, sharp" blue blades except when they were out of the other brand.
I also remember how sore my fingers would be till I figured out that a piece of card stock like the lid of a food container (cereal box or the like) then fold it over the back side of the blade and held with masking tape. This would help keep the blade a little stiffer and I could in return press down harder when the blade was pretty dull.
Also keep in mind that I was only allowed the used blades. Not a real bargain till my grandfather showed me how to sharpen the blades.
Take a 6 oz OJ glass and put water in it and slide the blade back and forth on each side till it was sharp again! Thanks Grandad!
Robert