I buy vellum at a paper supply store. Specifically, I buy UV/ULTRA II TRANSLUCENT PRINTING PAPER (radiant white). A ream (500 sheets) costs about $11 - $16. That's cheaper than the paper in 20 sheet packets at the quilt store. I download my pattern and print one copy. Then here's the trick I learned after struggling to figure out what color goes where on the pattern: color one copy of the pattern with colored pencils to correspond to the fabric you will use. I then number each stack of colored fabric I plan to use with the number that corresponds to the number on the pattern. Then I use my printer to make the necessary number of copies of the colored pattern I need and piece away. Of course, some patterns will require several squares that are assembled to make one big square. If those require different placement of colors and fabrics, make one master as described above for each different color placement required and then make the necessary copies. Remember to use really small stitches while piecing to aid in tearing away the paper when you are finished. Have fun!!