Choose-a-size box

thingiverse

You can create a customized box with a sliding lid by adjusting the dimensions of x, y, and z coordinates, which will give you precise control over the outer dimensions of the box. I've successfully printed it in PLA using my Wanhao 3D printer without any support structures. The design is compact enough to print in one go on most standard printers, but larger boxes may require splitting into two files to fit within the printer bed.