I do label my quilts and I sew the label to the back before I send it out to be quilted by my fantastic longarm quilter. Many of the quilts I am currently working on are projects that my Mother started and will eventually be gifts to other family members. I usually embroider the name of the quilt onto a piece of white or off-white fabric for this step I use my embroidery machine. Then I move to my light box. I tape a paper on the light box that has been printed on the computer using a 12 point font usually in Arial. The paper copy includes all of the wording with correct spelling and the spacing seems to be okay. Then I tape the fabric with the embroidered name on top. I use painter's tape for this step. Then I trace over the computer generated wording using a Pigma pen. My preference is to use the 0.5 size. When the tracing is complete, the label sits for at least 24 hours (this can be hard) so the ink doesn't bleed when I heat set it with a dry iron set on cotton. I attach the label on the lower right corner looking at the back and I make sure it is at least 8 1/2 inches from each edge. Sometimes I set the label into the back fabric and other times I turn under the edges or make a frame and sew then sew the label to the back by machine.
Have fun!