Changing Ink Colour on Heidelberg Windmill

much the same as an offset press. If your going from a darker to lighter color the cleaner the rollers and disk the less contamination you’ll get. You may have to do a “color wash” which simply means cleaning out the rollers after they’ve been inked with a lighter color to remove the darker contaminate.

Going from a lighter to darker color is obviously more forgiving. It does depend on the color though. Going from a dark red to a dark blue may give you ink a bit more purple look and need a quick clean to get rid of it.

In all honestly it only really matters if your have to match work from run to run over time or you need to match a standard color. otherwise whatever your happy with is good.

Washing up a windmill takes about 10 - 15 minutes, and involves both an automated washup system, as well as a final roller wipedown by hand. As mentioned above, the intensity of the washup depends on your color choices.
On any letterpress, it is good habit to wash the rollers thouroughly, which means at some point, wiping down each rubber roller by hand with a rag soaked with press wash. Good roller cleaning will not only keep your colors running true, but it will also keep you rollers in good shape, preventing glazing or premature breakdown.
someone has to do the dirty work.

Thank you both for your replies. That makes sense re: colours. I would embrace the dirty work out of respect for such a fine piece of machinery!

Kerosene is preferred as a washup solvent. If you have, (not likely on a Heidelberg), composition rollers, DO NOT USE OFFSET BLANKET WASH OR ANY OTHER PRODUCT MADE FOR OFFSET ROLLERS, This will harden your rollers to a point of being useless.

a popular choice is also California Wash, a product made by Varn. I see alot of the letterpress folks using it. It does a great job on both oil and rubber based ink, and it is not really too harsh. Boxcar press sells a very comparable product.