My daughter got a set of 70 colored pencils for her birthday. They looked sorta cool in their plastic store container, but it was to flimsy to keep around. So I thought I wanted to make a nice wooden pencil holder, but I know I couldn't hand drill the holes without some noticeable variation in placement of each hole, so I through this hole guide together. The holes are 8mm diameter, and the centers are 13mm apart. I used a 19/64" index drill to drill the holes.