Designed this for the Wife in Fusion 360 I used PLA or PETG at 25% I'm sure you can go down as low at 10-15% on the base though. I found that 25% on the lid was perfect. My first design took a little playing to get the lid to slide back and forth smoothly. So before I uploaded this I smoothed out the edges buy rounded them a bit. Should help the lid slide much easier. The dimension of each slot is Length-155 mm, Width-18.6 mm, Height 19.5 mm