I use press-n-peel blue transfer paper for my resist. It's available by the sheet at Whole Lotta Whimsy or by the package at Techniks. You have to use a toner based copier or laser printer to print your art, inkjet printers don't work. I have an inexpensive desktop laser printer that works great for this. I just make sure the toner cartridge is still printing very black. Since the paper is expensive, I just print what I need at the top of my document, that way I can trim the paper and keep running it through. You can also draw right on your brass to make the resist - I find oil based black markers hold up the best.