I do a lot of blackwork designs for use on various POD sites such as zazzle (see my store in the site menu). I also do some for clients.  They are not for free use, but if you contact me I do allow use of some designs in exchange for a donation, (suggestion is $15 for a one time personal use such as for a tattoo, more for others.) I can provide an un-watermarked file.  Some are commissions and are not available for ANY use, please respect the rights of myself and the commissioner.