I am wondreing, were older inks like those produced in the 30's 40's waterproof, or would they all run if wet?

Thanks!

Depends on whether or not they had an iron component. Any vintage ink which did not, is liable to some running.

In general were most older inks with iron? or waterproof? or not?

Most were not waterproof. Some made that clear in the label, for example, "washable blue." If the label said "permanent" they were more water resistant, but normally not fully waterproof. The principal type of "archival" ink normally was based on iron gall, which is very acidic and some would argue could corrode metal parts of the pen (aside from gold, of course). Whether the iron gall inks would eventually "eat" the paper would depend upon other factors, such as whether the paper was buffered (as many archival papers are), and whether the page got moist.

For many uses, such as school work, a washable ink was considered highly desirable. Stains of washable ink on clothing would generally wash right out.

You cannot generalize, really, as all major manufacturers made both washable and permanent inks (the distinction really applies to clothing, not paper). There was, as always, a market for permanent ink, and there were a large variety of waterproof drawing inks available in many colors (although carbon black was the most permanent, I suspect).

There were quite a few colors available, too, but I suspect supplies were rather restricted during the war, just like everything else.

Aniline dyes were widely used, and quite a few were suitable for use in ink, but the most popular colors were, I believe, blue, black, and blue-black, just as those are the main choices for business use today.

Peter

True, I assumed the question was about fountain pen inks from the period. If you have vintage India ink or specialty ink, it is quite possible that it is permanent.