Good explanation from Jean. However, I have bought the cheap gouache at Walmart and it works quite well with pointed pen.
i should have included the full disclaimer about what works and what doesn't work....
because it always depends on the nib and paper.
you never know what's going to work until you try it.
if you can't get good results with the first brand you try - you can't assume that other brands will give the same results.
another thing with gouache - even within one brand, different colors behave differently.
some colors are slimy - others are notorious for separating - so you have to stir a lot more often.
and - regular watercolor is also very nice for lettering. again, i prefer the more expensive brands, but there are probably people who prefer the less expensive brands.
