I got some thin (2mm) paracord to lighten my backpack, and it does make a bit of difference, just the lines for my tarp goes from 87g loose to 44g on a spool. And the spool is much more important for this thin stuff as it's much more likely to tangle up.

Printing

Print with enough walls to make the thin sections all walls and no infill (4 walls was enough for me).

PLA might be fine but could warp if left in sunlight or in a hot car, PET-G should be enough for most cases.

Use

The spool have have two halves, you can use each half for about 10 meters of 2mm cord. On the one for my tarp i have one half for the ridge line and the other for 4 guy lines.

It has 4 holes to attach carbines or loops, or tie the ends of lines to to avoid unwinding.  Loops on the ends of lines can be hooked over the corners.

Also for amateur radio

It would also be used to wind up amateur radio wire antennas (or other wires), the two halves of a dipole could be winded separately on the halves of the spool.

Size

Length: 133 mm
Width: 70mm
Height: 3mm
Hole diameter: 9 mm

Make it your own

You can copy and modify this design with Onshape: [https://cad.onshape.com/documents/99bc1f7f3ffc988d2f2aef99/w/3d523ba182e17690c1624af8/e/85edc3f898e1f4d01c47dcd7?renderMode=0&uiState=62446b8aa16de869d095c5ee](https://cad.onshape.com/documents/99bc1f7f3ffc988d2f2aef99/w/3d523ba182e17690c1624af8/e/85edc3f898e1f4d01c47dcd7?renderMode=0&uiState=62446b8aa16de869d095c5ee)