After having one (too many) cologne sample vials break in my pocket, I decided it was time for a change. And 3D printing and TinkerCAD came to the rescue!
This design is not finished yet as it is too short for the regular sample vials on the market. I designed in a rush because it was open night at the maker lab and everyone wanted a turn on the 3D printer.
The notch in the lid was a happy accident that wasn't initially in the design, but it helps take away some of the stress off the cap, which is held in place by friction.
I intentionally buffed the ridged 3D printer texture in order to make the cap slide on better. Hope you find it useful and adapt it for some use.
Start with the measurements of the sample vial. Add 1mm wall thickness and 2-3mm bottom and top. The notch in the cap is 2mm.
Buff away imperfections with a Dremel.