So, I've pretty much decided I have a major bug for physical maps, since I started experimenting with them during my hiatus from the guild (when family is over and all crisis-ridden, they don't judge one for having a sketchbook in hand, but they do judge for being upstairs on the computer).
To that effect I've been doing a lot of experimenting with different materials for ink-and-watercolor (since that particular style is my passion), and I thought I'd post my lessons learned. Thread will be ongoing as I discover more, but this stuff is expensive, so if I can help some folks save money by buying the right stuff to begin with, I'll be happy :)
Handprint.com guide to watercolor pigments -- this is THE most awesome resource. It's a bit intimidating at first, but this is how you find out if the stuff below applies to a certain paint you're thinking about buying.
Ink DOES run. The only ink i've found (and I've only tried "waterproof" inks) that actually stays put when you then make the paper wet and/or brush over it with watercolor is Speedball's black calligraphy ink. Other colors by Speedball run. Other brands of acrylic "waterproof" ink run. So if you're going to use anything but that ink (or one you've found and TESTED) paint first, then ink.
Note: I use ink and dip pen. If you're using actual pens or markers or whatnot this doesn't apply -- but still, do NOT trust that it won't run just because it says permanent or waterproof. Most aren't.
Pencil won't erase. Once you paint over pencil with watercolor, it's there for good. For some reason, the watercolor seals it or something. Erasing it does nothing -- but it will mess up your paint. So unless you're going to paint dark or ink it, erase to a "ghost" before you paint it.
Granulating paints >>> non-granulating paints. It turns out that for artistic mappy stuff, the texture imbued by granulating paints makes a HUGE difference in the end product. Check at handprint (above) to see if a paint is granulating.
Staining paints > lifting paints. Other watercolor map makers may disagree I suppose, but I've found that glazing (painting layer over layer) is the easiest way to paint after being used to using layers on a digital map. But if you don't use staining paints, they mix instead of layering, and it ends up looking muddy.
Paper matters. When I started, I grabbed cold-press watercolor paper because that's what the art store carried. I've found that cold-press sucks for the way I paint maps. Not only does the MAJOR texture make it really difficult to use a dip pen, but it soaks the liquid and dries FAST. So I can never get a sea painted without lots of horrible drying-lines and just general screwups. I have some new paper coming in tomorrow and I'll post up how that works.
Have scrap. And not a sketch book. Have scrap paper next to you that matches the exact paper you're using. (I use the back of failed projects, ripped into smaller sections). Because a dip pen will work perfectly on sketch paper and then blob like the dickens on your watercolor paper and then your project is ruined. Test the pen on the scrap, adjust as necessary, test again, THEN touch your real project.
More to come after tomorrow when I get my new paints and paper and can do some more experimenting :)