My version of spool storage

Units of 2 spool slots can be stacked vertically. Stacks can be connected to make them more stable.

Inner width of a spool slot is 75mm.

No support is needed.

Items clip together with just a bit of force. No glue is needed.

Number of elements needed for 1 stack

3 side elements per unit

8 top-bottom crosspiece items (4 top, 4 bottom)

4 middle crosspiece items for each additional unit stacked.

Assembly of 1 stack

Place 3 side elements onto 4 top-bottom crosspieces.

Place 4 middle crosspieces on top of side elements

Add anther 3 side elements

Continue with this pattern until preferred number of unit is achieved.

Finish the stack with 4 top-bottom crosspieces on top.

Connecting stacks

There are 3 element: top clip, middle clip and pin

Add pins into holes of side element and press 2 stacks together.

Reinforce stability my connecting ends of side elements with clips

Labels

Just couple of plates with basic material names, prepared for 2 color print.

Labels are placed on the front crosspiece of each spool slot.