Streaking when printing with gold ink on Vandercook SP15

I am having problems figuring out why there is so much streaking on this print job on my Vandercook SP-15. I was using 236# paper, and gold metallic ink. The thickness of the paper is always an issue but I haven’t had such bad streaking before. I’ve been adjusting the roller height over and over, and am now using 184# paper, and while it is better, the ink still looks uneven — particularly the lines of the tiger illustration. Can anyone advise on what else might be the issue?

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I’m sorry I can’t see your streaking issue well enough to comment on it. However, there are some other things that you might keep in mind.

Printing metallic inks on relatively rough paper doesn’t work well. Most metallic pigments which are designed to have a metallic look, are now tiny flakes of aluminum. (In the case of gold and colored metallic inks, they are aluminum flakes with transparent colored pigment added). These flakes, when printed, must be able to lay flat on a smooth paper surface to give a metallic look, or sheen. When printed on rough paper, the flakes don’t lay flat. Instead, they lay all over the tiny hills and valleys of the paper, at many different angles. Thus, they create little to no sheen. Perhaps this is part of your problem.

Another problem with printing such thin lines of gold is that there wouldn’t be enough inked area to see much of a metallic sheen even if you were printing on smooth paper. You need bolder lines and/or bigger areas of ink coverage for that.

Please don’t think I’m being picky. I’m trying to help. Many of us learned these lessons long ago, and we’re just trying to keep you from having to re-learn them.

Best regards, Geoff

You might try metallic powder dusting, spreading a SMALL amount of powder on the sheet and twirling it to get the powder into the wet ink, then inverting the sheet over a newspaper or plastic and banging off all the excess powder. This may not work on a very rough, deep surface.
Be sure to WEAR A MASK!
The result, when dry, will probably not survive ungentle handling or sliding other sheets over the surface, so should be sprayed with a fixative. Good luck.
Frank.

A two stage approach might work. Make an impression using opaque white or yellow ink. This will flatten the image area and provide a base for the metallic ink. Next make a second impression with the metallic ink.

Thank you all for your feedback. I should have mentioned that this is the 9th year I am doing these Chinese New Year cards, and I have not had problems in the past. Same metallic ink on 236lbs Reich Savoy paper. Though I have used several different presses over the years. Here’s an example of the ram card from a couple of years ago. The ink goes on evenly. So I am still wondering if it is an issue with my rollers or base. Also attaching another photo of the most recent print using 184lbs paper. It’s better, but the ink is still uneven. Help!

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When you told your machine minder that it was a metallic ink run you got a depressed reaction. They well knew to expect some problem or other. The damn stuff wont roll out well, it sort of hangs in the ink duct, you get set-off on the backs of your sheets with the slightest height pile. And when you had a bindery lady alongside you doing the powdering version, she had to have a third of a pint of milk, in mid morning and mid afternoon break. Why? because the grinding of the metallic powders used a sot of lubricant that was very bad for you indeed. Masks certainly. But this was all a very very long time ago, and the metallic inks are miles better now. Theres even automatic machines just for powdering, much used in the UK in label printing firms.