Here you go- I did this for the
NFAS board:
Get some 'waterslide decal paper'- I get it off Ebay, and it comes in clear or white. Clear is best if you have tricky borders on the graphic and don't want to spend hours cutting it out, white is the only choice for most flags- your printer doesn't print white. The colours will be brighter too. Bear the background colour of the shaft in mind.
Now find a pic you like on the interweb- hint: switch the adult material filter ON when searching images- you won't believe the things I found when I was looking for snakeskin. Interesting, but time comsuming. Copy and paste, and manipulate the image to your heart's content. Do a few dummy runs on regular paper before you waste the waterslide stuff- and cut and try the dummies on the arrowshaft too!
I like to add my name, the spine rating and point weight of the arrow too- memory like a sieve.
Right, print on your decal paper, let the ink dry, and spray on a SINGLE thorough coat of clear polyurethane- I like PlastiKote gloss. Don't be tempted to use the water based brush-on products- the ink will run. And stick to a single coat of poly- too many coats will make your decal too thick and stiff to adhere well to the shaft.
Once dry (8-24 hours depending on temp and humidity) cut out the individual decals, and clean your shafts with a bit of alcohol or whatever. Soak the decals in cool water (warm water makes them wrinkle when you apply them) and slide them off the backing and onto the shaft when ready (about 40 secs). Slide them around to get them in position, and work out an air bubbles that got trapped. They're nowhere near as fragile as model airplane transfers, by the way.
Leave to dry (24 hrs), seal with 2-3 coats of poly (you can use brush-on now, if you prefer) and you're done.
Hope this helps.