Having experienced the ugliness, the hassle, and the snails-eating-the-ink off problems with paper tags, what I use for crosses are paper clips. If you shop around (including on eBay) you can get lots of different colors.
I have basic colors: red, orange-red, orange, pink (I've learned that the sun can fade color so I use these shades all for the same pollen parent, or else make sure that the pollen parents are not used on the same pod parents so there can be no confusion, if that makes sense), 3 shades of green, 2 shades of blue, 2 shades of purple, white, yellow, 6 striped combos, 4 metallic colors... If I am using more pollen parents than that, then I start doing combos (striped red/white + lime = X, striped red/white + blue =Y and so on).
