I made this for work, as we had razor blades laying on tables and on magnets just out in the open. 

These allow for Single Edged Razor Blades to be stored, with the blade side sheathed. They're magnetic, so the holder can be oriented in any direction and the razor blade should not fall out.

The design uses 8mmx2mm magnets.

Print Settings: 

Print vertically with the "mouth" facing up while using whatever filament you would like. 

The rest are optional (but what I found to work the best)

3 Walls at .24 for Outer, Inner, and Top Surface

35% Gyroid Infill

5 top/bottom layers (could use 3)

Auto Tree Support (Less Support)

5-10mm Brim

Takes about 40min to print. (With Prepare Time)

I do plan on making a v4 with a chamfered base instead of a filleted base making printing a bit better.

I also plan on taking actual pictures of a completed holder.

Feel Free to leave any suggestions in the comments!