print away! just let the ink dry before using the papers. the only time i ever had a problem was not paperpiecing...with paper piecing you sew right on the lines, so it is not going to show anyway. when i messed up i drew on plastic cling wrap with a sharpie, then stretched it across a quilt top and quilted...and the black marks went right onto the quilt top, and being a sharpie were permenent :(
but lots of people use it just fine without mis-hap. i guess i did not let the ink dry enough. but again, with paper piecing it would not matter because you sew on the lines and they are inside the seam allowance.