If you ever see blurring or bleeding on the printouts, this is usually due to moisture absorbed in the icing (eg through humidity).

One way to reduce this moisture is to dry out the sheets before and after printing (eg by placing them in a fan oven or placing them on a heating plate). This in turn will help to keep the image crisp. Additionally, once dry, place within a zip-lock bag away from direct sunlight to help to preserve conditions.