I have giving y'all many examples to create something with just a limited amount of colors. You don't have to buy a special pack. However i would recommend go to either Staples or Office Max for they have a larger selection of pens than Walmart or Target. One more hint..don't use any art paper (it will bleed)..this is a office medium so the proper choice would be posterboard or card stock paper. Warning! This is a unforgiven medium. You make a mistake your better off throwing it away and starting over.So who is up for the challenge?