I (like many of us!) happen to have many rolls just cluttering up my work area. Inspired by Joel's shelf, I designed a beefy version. The 40mm wide bracket is tough, has nice lines and encloses the wood nicely. I included a 20mm version as well.

The 40mm brackets print out at a bit over 200 grams, so plan accordingly.

The spool holder is a work in progress and may need some TLC to become great. I used wood dowel, you can use plastic 3/4th's pipe too.

I printed at .2, it would be far faster at .3 layers.