I'm told that many people use Zig-Zag cigarette rolling papers to make their paper cartridges. I haven't tried that, but hear it works well.
Myself, I bought a couple containers of Saltpetre from the druggist years ago. I mix three or four heaping tablespoons in a quart of water, and stir until it's well dissolved.
Then I cut regular printer paper into fist-sized squares. I pour the liquid solution into a glass baking pan, then add the squares of paper. When the paper is well-soaked, I hang it up to dry on a line with clothespins.
This time of year, when it's cold outdoors, a couple of suction cups on the tiles of the shower will hold a thin line from which to hang the paper and let it drip-dry.
(Hey! I heard that! Someone muttered, "The ol' nasty cat must not use his shower often." I'll have you know that I shower at least once a month, smartypants!
)
Anyway ... when the paper is dry, it's ready to make cartridges.
Store the solution in a plastic container with a plastic lid. The solution will rust a steel cap.
For .44 caliber, use a length of 7/16th dowel, about 6 inches long, with the end sanded down to a taper. For the .36-caliber, use a 3/8 inch dowel that's been sanded down to a slightly smaller diameter. Or, sometimes, you can use 5/16th dowel.
The dowel will be used to form your paper cartridge, which must be slightly smaller than the chamber so it slips in easily.
Determine your powder charge, which will dictate the size of the paper slip you'll be using. Cut the paper to size from the sheet.
Roll the slip of paper around the end of the dowel, leaving a little extra hanging off the pointed end. Glue the paper's seam with a tiny swipe of rubber cement. A toothpick helps. Now, you'll have a tiny snow-cone or cup, to which you add your powder.
Fold over the little tail on the tapered end, and secure it with a thread or a dollop of glue. Or use both, with the thread holding it in place until the glue dries.
Allow to dry, if you used glue.
Add your powder charge to the open end of the paper cartridge. Fold over the end and secure with glue. You can also attach a conical bullet to the end of the paper cartridge but I rarely do. I find that using the paper cartridge, without projectile attached, is easier.
I don't often make paper cartridges. It's time-consuming and I find it much easier to just use loose powder.
The paper cartridges can be carried in tiny, plastic tubes with stoppered ends. Or lay them flat in a small tin.
In the old days, Colt's paper cartridges were carried in a small block of wood with six holes bored in them of the appropriate size. The block was then sawed in half lengthwise. The wood block then had a string placed around it, leaving a tail end, and then wrapped in heavily waxed paper for waterproofing.
In use, it worked fairly well. You grabbed the tail end of the string that stuck out of the wax paper, pulled it to tear the wax paper all the way around the block, and each half of the wooden block opened flat, to expose the cartridges.
Samuel Colt's first such cartridges were assembled with tin foil, not paper. (real tin foil, not aluminum foil). The quality of American tin foil was poor, so he ordered the tin foil from Germany, which had a long history of toy-making and used tin foil for toys and other uses.
Very, very few of those first tin foil cartridges exist today. They are among the most sought-after examples of early American cartridges. Cartridge collectors pay a premium for these early tin foil Colt's cartridges, on the rare occasions one becomes available.
A full, sealed box of real Colt's tin foil cartridges would be worth many hundreds of dollars, perhaps thousands.
After a year or few of producing tin foil cartridges, Colt's began using combustible paper. It was cheaper and easier to obtain.
It's good to have a few paper cartridges on hand, to show others how the old timers loaded their guns, but they're a bother to make.
If you want to carry a few reloads in the field, in your pocket, you would probably do better to purchase a small powder flask, such as that made for the .31 Colt, with a nozzle that holds the desired powder.
If you can't find a .31 nozzle (nozzle? dang ... it's nearly 1 a.m. and I've forgotten it's proper name! But you get the gist) of the right capacity, buy one that holds half the charge you want, then just charge the chamber twice.
Or carry a little measure and use the flask to dispense into the measure.
Paper cartridges are fragile. It can be a challenge to carry them in the field, without damage.
The old, Colt's system of the split wooden block, wrapped in wax paper, was pretty good. It would still work today.
God knows where you'd find real tin foil. I'd rather use combustible paper, to ensure every bit of it is consumed.
I'd rather carry a small flask and measure.