Where to get lens caps

[GraphicGrammarian]

This kind of thing will totally be 3d printable. Have you checked thingiverse or similar?

[ajmiller]

I buy caps off eBay, advertised here in the Uk as "Lens Cap End Cover Binocular Monocular Camera Spotting Scope Microscope Eyepiece". A mouthfull but they do the job and come in loads of sizes. Especially useful for protecting my brass lenses.

[j.e.simmons]

For some of my LF lenses I've found that PVC pipe caps with a little felt glued inside make good caps.

[Mark J]

Ebay is fine for getting used push-on caps of various sizes - I just bought two for a Rodenstock lens I'd bought without caps.
3D-printed materials are too rigid and not very good for the job.

[notorius]

I buy caps off eBay, advertised here in the Uk as "Lens Cap End Cover Binocular Monocular Camera Spotting Scope Microscope Eyepiece". A mouthfull but they do the job and come in loads of sizes. Especially useful for protecting my brass lenses.

Thank you for that hint/link!

[notorius]

For my brass lenses which came without caps I made a new ones using a hardpaper and ink. I think it is a suitable fit for such lenses. For a modern lens I would try something else, just like ajmiller suggested above.
As a back lens cover for my Mamiya TLR lenses I found that bottle caps from 5l deionized water bottle(here in Czech Rep.) are perfect match. Nothing fancy, but it works just fine.

[maltfalc]

https://www.thingiverse.com/thing:5793382

[MichaelGJ47]

EBay came through ,waiting for. Them to arrive

[Gabe]

Linhof Studio UK sell original Rodenstock and Schneider-Kreuznach lens caps.

[Willie]

http://lungov.com/wagner/DIYLensCap.html

Just one of a number of online references to make lens caps.