That is correct. One shot means "per print," not per print session. With the gold, palladium and platinum formulas I give in the article at unblinkingeye.com you will need a minumum of about 20ml for a 5X7 print, 50ml for an 8X10, and around 100ml for a 7X17. Use the solution once, and discard. Toning to completion with this formula can take up to ten minutes, even though visually toning may appear to be complete at around five minutes.