@ Erica: I saw a previous post from you about Aquanet hair spray & so I tried that. I also tried a fixative that a professional calligrapher told me to use when I was addressing my daughter's wedding invitations. - After they would dry, I would stack them alphabetically & the ink would sluff off on the back of the envelope above the envelope in the stack. I kept having to erase & erase, but I had so many invitations, I HAD to stack them. I'd bought some nibs on eBay from a lady & so I contacted her & she told be about the fixative. It smells TERRIBLE, but it worked, just as it was supposed to! I sprayed these envelopes with fixative prior to applying ink, once I saw how much they were feathering and puddling. It helped a little, teeny bit, but not enough to make the finished product successful.
I've never anything but ink from the bottle (well, in the beginning I tried several calligraphy pens, but never found any that I liked the "thicks & thins" of, so I switched to an oblique holder and nibs & never looked back!). I've been afraid to try the gouache, as I don't know how. I know that there are videos on the Internet, so I guess I'm going to give it a whirl & see how I do! I also think that I have a new book that the author gives a tutorial on gouache in... I'll give that a try & will report back! I'll also post a picture of an envelope with ink, as pitiful as it will be...!