These bins are designed to fit the Toyo Steel T-152 15cm Toolbox. These STLs use 1.2mm wall thickness, so should require only 3 perimeters with no infill on the side walls. I have found this to be the best compromise between print speed and strength. I have printed these and both PETG and PLA. For my use, PLA has been plenty strong enough. I have made the same profile bins for the T-150. The tops of the bins have a fillet applied. Two T-152 bins of the same size can stack on top of each other and fit inside a T-150. For those who would like to custom model shadow-boards into their bins, the CAD file is also available in Fusion and Sketchup formats. Leave a comment if you need something else. Made with Fusion. Free to use and remix, please link back with a remix, I'd love to see what you come up with. -Mitch