Inking/roller issues

Hello. Universal Hand III. We just changed our rollers. Since the switch, the ink has not been laying right. It slurs up the side of the impression. There is a space of paper showing through in between the well of the impression and the side of the impression. It feels like the rollers are not getting clean enough. The rollers are from NA Graphics and they have microscopic grooves running along them unlike our old rollers that were smooth to the touch. We use vegetable oil (Crisco) and Mineral Spirits to clean. I don’t think its a roller height issue (however, this is the first time I have ever adjusted them). I tried to capture a photo of this. Any thoughts? Thanks.

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Here’s the photo

image: photo11.JPG

photo11.JPG

The rollers should have a bit of “tooth”, microscopic roughness which helps to hold ink on the roller. The rollers should not have grooves which are directional, or in a particular pattern.

It could be that the new rollers carry a heavier film of ink than the old, glazed ones you replaced. It also may be that the vegetable oil is getting into the grain of the roller and needs more washing to be clean, and thus is altering your ink. Try backing off on the amount of ink and see if your image sharpens up. It is difficult to see in the photo what you have described in your query.

Try a wash with just solvent (no oil) and see if the situation improves.

John Henry

It sounds as if the rollers were turned on a lathe. The “slur” on the image could be caused if the rollers and trucks are not equal in diameter. If the rollers are too small they will skid across the plate and ink can pile in several places on the plate. If they are too large they can pile ink on the lead edge of the plate and raise the trucks off the rails. The extra pressure on the rollers might explain the other image problem you describe.
-edd-

image: Rollers-Trucks.jpg

Rollers-Trucks.jpg

Rubber rollers are actually ground on a lathe — the raw rubber is wrapped around the core, then vulcanized on to same, then wet ground to tolerance on a lathe. The pattern is normally fine enough that it creates “tooth” that holds the ink, though the real ink holding ability is related to the surface chemistry of the composition of the roller, the hardness of the roller and the composition of the ink. NA Graphics’ rollers are made to industry standard in terms of surface finish, composition, and hardness. Suffice it to say that the slurring is more likely an over inking problem or a roller height problem than a roller problem.

There are no trucks on a Vandercook UNI III, so this is clearly not the issue.

Didn’t realize it was a Vandercook. In that case, roller bearers might help you. However, as Jeff suggested, too much ink will cause image problems. As for the void areas, check for cupping on the plate. I have experienced poly plates with low areas on the inking surface.

Thanks folks. I really appreciate it. I’m gonna back off on the ink and clean with just the mineral spirits. I’ll see if that helps. Thanks again!

I just took off some ink from the rollers, it was way too easy. It glides off with just a clean, cotton rag instead of making me work to get it off. After removing ink, slurring continues and the ink coverage is ok. It looks passable to the untrained eye.

Also, cleaned the rollers with just the Gamsol. They don’t look clean still. Worked on them for a while and they still look dirty. Any suggestions? California wash? I’ve never used anything but crisco and gamsol.