However, drawing papers are not generally a good choice for alt processes because they have little or no sizing and thus are too absorbent.
I've made many successful cyanotypes on all kinds of drawing paper, ranging from fairly sturdy 160gsm papers all the way down to flimsy 60gsm sheets so thin you can see through them. While the latter require a lot of care in processing, the heavier drawing papers I found to print perfectly fine - even with their carbonate buffers that they likely all have.
My recommendation would be to head out to a local arts supply store and pick up a dozen or so papers and try them out. If none work, go get some more, but odds are that if you buy 5 papers, 1 or 2 will work just fine for regular cyanotype. It's the least picky of all processes.
Yes, if you want to get the absolute best maximum density etc, you'll have to find the best paper, and/or pre-treat papers etc. But to get nice prints in an educational setting, many, many papers will do just fine. I very rarely make cyanotypes anymore these days, but a few months ago I did some when playing with staining developers. Here's a print I made in that process:
It's made in generic copier paper, 80gsm - the kind you pick up in any stationary shop in 500 sheet packs. This is not to show that copier paper is somehow the best choice, but to demonstrate that paper selection doesn't have to be intimidating.
(The low contrast in the print is because it was made with a negative that only consisted of a dye stain image - all silver was bleached out. Good contrast was just as easy to obtain with this paper).
I understand, and we're not helping. I apologize.
My recommendations:
* Buy some potassium ferricyanide and ferric ammonium citrate. Any shop is fine. A ready-made 'kit' is also fine if you don't mind paying the premium.
* Buy a jar of citric acid and some cleaning vinegar from the supermarket/drugstore for acidifying the wash water. It takes just a pinch of citric acid or a small squirt of vinegar. Tap water is fine.
* Get a range of affordable papers from the arts supplies store. Pick papers that appeal to you. Doesn't matter if they're watercolor, etching, drawing papers etc. Drawing papers are generally affordable and many print just fine. Yes, there will be differences, and some may be duds, but odds are you'll hit upon something that does work right out of the box.
* Buy a brush. Pretty much any kind will do. A 2" or 3" generic painting brush from the hardware store will do fine. A foam brush will also work. No need for expensive hake brushes etc.
* Use a picture frame for initial tests. Or just a sheet of glass weighted down on the edges. Later on you can always upgrade to a proper contact frame.
* The sun is a good light source. Printing at night or on cloudy days works fine with a cheap UV floodlight in the 50-300W range. These probably start at around $35 or so these days. (e.g.
something like this)
In short: keep it simple and
just get started! Don't overthink this. Just get going, experiment, see what you run into and then solve it. Don't aim for getting it right the first time. There's no need. The fun of cyanotypes is that it's a process that works well with humble, affordable materials.