The website both Cliveh and I mentions, tell you to use a pestle and mortar to crush the flowers. I used a garlic press. Much quicker and easier. Make shure to cover up the workplace and use rubber gloves. The stains the flower sap makes is hard to remove.
I've found it hard to keep the sheet of paper flat after several coats of wet sap. I was thinking about ironing the paper when the painting is done. Not shure if this would affect the anthotype prosess.
I'm not shure if you knew, but anthotypes can't be fixed. After a while, the picture will fade. Keeping it in a dark place can prevent this. You could scan and print, but that takes away some of the magic of creating an anthotype.