Cracks in my table

I really LOVE the cracks in my table that LaVern made for me. This morning I found another use for them. For those of you who have ever purchased fabric at a store that has the nice big counter with the groove down it and they line up the material and follow the groove with the scissors so a nice straight line is cut. Well, the same holds true for a table with a space between the boards. I lined up the Christmas paper on the bottom edge and followed the crack. Straightest Christmas paper I have ever cut! I'm thinking a really sharp razor blade might work nifty also but wouldn't know where to begin to find one.