after 30 yrs of use on my 6 x 24 it's got nicks in the edge because i get too close to the ruler. I did have my 12 x 12 warp after 20 or so years. I hold onto mine forever. i'm too cheap to buy a new one. I still have my original rotary cutter. Remember when if you bought a quiting book, you'd get a free small rotary cutter? I have 3 of them. and yes, it takes me forever to change a blade. then i ask why i waited so long.