Here are a number of boxes composed of squares. They might serve as a set of containers for stationery items.
They are derived from thing:77843 Containers Composed of Triangles. Square boxes are easier to construct; the openSCAD code is simpler and more parametric.
Seven stl files are supplied. Their names are derived from the size of the basic motif, 3x3, 4x4, 5x5, or 6x6; the length of the side of a square in mm, 6, 8, or 10mm; and whether they are a full or half height box.
Stl files are:
box_3x3_6_half.stl - 38 x 38 x 21 mm
box_3x3_6_full.stl - 38 x 38 x 38 mm
box_3x3_6_fullx2.stl - 38 x 38 x 75 mm
box_3x3_10_half.stl - 62 x 62 x 33 mm
box_4x4_6_full.stl - 50 x 50 x 51 mm
box_5x5_10_half.stl - 102x102 x 53 mm
box_6x6_8_half.stl - 98 x 98 x 51 mm
The openSCAD program that created the files is make_sq_container.scad.
The boxes print most rapidly if done directly on the build platform.
The openSCAD code is partially parametric and an extensive range of sizes can be constructed.