I just found some fantastic pens for mapping. The’re called FRIXION colors and they are made by Pilot. The pack I got comes with 12 colors (just like the picture), they don’t bleed through the paper and best of all they are erasable! With these pens you don’t actually rub the ink away but the rubber type end of the pen when rubbed on the paper produces heat and the heat causes the ink to disappear. My family found this out the hard way, my father-in-law was preparing for a lecture he was going to deliver in a few days time. He had used a ball point Frixion pen to write out his linear outline (sadly not a convert yet) and my mother-in-law used his notepad as a convenient place to set down her hair straightener. When he went to go over his notes the next time you can imagine his surprise. So a word of caution, if you choose to use these pens for your next map don’t leave that work of art on the dash of your car in the middle of August.