I realized I needed a lens cap for my old brass lens when shooting the Ilford positive paper and hopefully one day to able to use them when shooting with collodion. The original ones are made of leather and are very difficult to find... they can cost you a fortune as well.
This is my quick solution, with a bit of practice you can master doing your very own lens cap made of cardbord
You'll need:
-some thick and some thin black card, I used black mounting board and a thin 210 gsm card.
-glue and spray mount.
-cutter
-compass cutter
Take a measure of your lens and using the compass cut a circle of the exactly side of your lens, try to be as much precise you can with this since it will be your base for the whole process.
You'll end up with a pinhole in the middle but don't worry about that now, just push the card back with a tip of a pencil to cover back...
Measure the circunference of your lens and cut 3 strips using the thinner card, the width depends on the size of your lens, mine were ok with 0.9cm.
Put some glue on the edge of the circle and apply one of the strips, hold for a few minutes until it dries.
Once is dried try on the lens to see if fits, it can't be too loose, a little bit is fine as it can adjusted at the end.
We're now going for the finishing and you can be as much creative you like, I just used the backpaper of a 120 film... it can be anything you want.
Put the lens cap on the top of the paper and ith a pencil draw a circle...
and cut like in the images below:
You should end up with something like this...
Apply some spray mount and place the lens cap using the circle as reference..
fold the edges tightly...
Apply some spray mount on the other strip and cover the edge of the lens for a nice finishing...
I've placed a tiny piece of card with glue to give some extra strengh on the strip that envolves the lens..
Now is time to adjust the cap to fit nicelly on the lens... cut some pieces of 1.5 cm from the last strip and glue inside right on the edge of the cap and try again. If still loose cut another and do this untill you get a perfect fit
And here it is...
Any problems just give me a shout !