Choosing the paper surface side

[ReflexBlueHorror]

(I posted a similar topic under Ink & consumables, but I'm specifically interested in this topic in relation to offset printing technique so have modified it for here).

My question stems from handling genuine sheep/calfskin vellum, where there's a smooth 'flesh' side that's prized for writing, and the rough 'hair' side that is not favored.

When you encounter papers which have this quality - one side smooth, the other rough or felt-marked (such as Zerkall or Munken papers) - however subtle it is, do you ignore it or make note of it for a particular reason?

 

[Ulrich]

I remember an issue (offset printing), but unfortunatly not the paper, what was unsuspected for that.
It is long time ago. A with the same CMYK-values printed darker blue leads to different colour on both sides of the paper.

It was not coated on one side and uncoated on the other, but there where different content filler (and surface smoothness, allthough hardly to feel, see and expect...)

Topic: (german language: "Schöpf- und Siebseite") / Creationside and sieve/screenside (?)

This is what the google translator say (from the Papyrus-site, a german paper vendor):


wire side

is the side of the paper that rests on the screen during sheet formation in the paper machine. It is often to be recognized by the slight imprint of the metal fabric on the paper surface, especially in the case of lower quality fibers. The screen side also contains fewer fillers, because some of these are sucked off the screen with the water. The side facing away from the screen is called "fair side" or "straight printing side" because of the smoother surface and the higher filler content. For this difference between the two surfaces, the papermakers have coined the term "two-sidedness".
Felt side, reverse side

 

[ReflexBlueHorror]

Thanks Ulrich. Your comments also enabled me to google some new terms and I found the English terminology for what you described in Neenah's glossary:

Two-Sidedness: In paper, the property denoting difference in appearance and printability between its top (felt) and bottom (wire) sides.
Felt Side: Top side of the paper, opposite from the wire side or underneath. The "right side of the paper".
Wire Side: Opposite of felt side, this is the side of the paper that was against the wire during manufacture. A watermark will read backward from this side of the sheet.
Twin-Wire Machine: A paper machine with two wires instead of one producing paper with less two-sidedness.​

Footprintcard's glossary also included some comments on the ink densities and the orientation paper is supplied:

Felt Side the top side of the paper, which comes in contact with the dandy roll and felts during the papermaking process. The bottom side of the paper, which comes in contact with the wire (forming fab- ric) or the papermaking machine, is called the wire side. The felt side of a paper may appear to be softer, while the wire side of a paper may have more “tooth.” During printing, the softer texture of the felt side of an uncoated paper may pick up slightly more ink than the wire side of the same sheet, and the printer may have to adjust ink densities to compensate for this. Paper is generally packed and shipped as it is made: felt side up. see also finish, papermaking, tooth, two-sidedness, wire side.​

That's intriguing the darker blue was affected! Did it shift in brightness/darkness, or to a different hue?

 

[Ulrich]

as i said: more than 15 years ago. What i remember is both, if not "all" ;-):

Brightness as well as hue, duller, more lax, less brilliance....

 

[gordo]

The wire side, because it has a screen pattern, can cause moiré with one of the process colors to appear. The moiré May appear as a subtle mottle in flat screened areas.

 

[davarino]

The wire side, because it has a screen pattern, can cause moiré with one of the process colors to appear. The moiré May appear as a subtle mottle in flat screened areas.

Thanks, Gordo.

I saw a job like that less than 6 months ago. Printed on a cheap-cheap sheet and it looked like a silkscreen had been laid on top at an angle; same image printed on the other side of the sheet nicely. We switched to a different (more costly) sheet and everything smoothed out.

(Added later: The job was being run on a Komori Lithrone 540.)

 

[gordo]

Thanks, Gordo.

I saw a job like that less than 6 months ago. Printed on a cheap-cheap sheet and it looked like a silkscreen had been laid on top at an angle; same image printed on the other side of the sheet nicely. We switched to a different (more costly) sheet and everything smoothed out.

Thanks. Most printers aren’t aware of this issue so they usually blame the halftone screening and waste a lot of time trying to figure out the problem.

 

[turbotom1052]

This is the very reason why I always tried to make my front cover "office copies" on the felt side of the sheet, or even would flip the paper, right off of the shipping skid, to be able to run the potentially problematic images on the felt side of the paper.

 

[Alois Senefelder]

Gentlemen,


Clarification: The terms Wire side and Felt Side are irrelevant, all the worlds uncoated paper including the base paper for Coated ARE

manufactured on Twin Forming Paper Making Machines.

Davarino and Gordo, IMHO what you are seeing IS - Ghosting.

Regards, Alois

 

[Alois Senefelder]

Hello fellow Lithographers,

Qualification regarding my IMHO comment to Davarino and Gordo, I'm NOT talking about Roller Train Inking Ghosting, more about

Mechanical Ghosting on Heatset Web Presses.


Regards, Alois

 

[PricelineNegotiator]

Mechanical Ghosting on Heatset Web Presses.

In more exact terms, this is the old press operator haunting the machine. I've seen this issue before on Ghost Hunters (show on A&E)...there is no fix unfortunately as a press operator's soul is infinitely intertwined with the machine. You'll have to get an entirely new press. Sorry.

 

[gordo]

Hello fellow Lithographers,

Qualification regarding my IMHO comment to Davarino and Gordo, I'm NOT talking about Roller Train Inking Ghosting, more about

Mechanical Ghosting on Heatset Web Presses.


Regards, Alois

I first heard about this issue from the technical director of a major publisher of headset magazines. He showed me samples and how the switch to FM screening eliminated the problem. He later did a presentation on the issue at a GATF Technical Conference.