micron pigma pens---they are archival quality- acid free- do not bleed- do not fade-do not skip- are permenent- cost around $3.50 apiece--some quilt shops carry them- they can be found at Joannes- hobby lobby- michaels- clotildes- keepsake quilting, nancy's notions--and many other sources-
they come in a variety of colors- and are fine tipped-
you do not need a (fancy printer) to print labels- in fact the (not so fancy's) work best.
you can iron freezer paper to (pre-washed) muslin (do not use fabric softener when you pre-wash-do use detergent)
cut the muslin/freezer paper to the same size as a sheet of printer paper. then you can design your label on the computer and print it on the muslin- set aside to (cure) let the ink really dry- soak into the fibers- then heat set.