I also sharpen my blades. Can be done as fast as hunting a new blade and changing it. I use a stone that belonged to my dad.

As to covering, I used to cut covering on glass with xacto blades and of course dulled a great many. I now use a rotary cutter and seamstress mat, which seems superior.

I also agree with use of two knifes with red tape around the handle of one indicating it is reserved for use where it won't be abused.