How far back should the side-register mark be and why?

[otherthoughts]

For sheet-fed presses, whether you create a hand scribed side-register mark on a flat or create a digital side-register mark with an imposition application is of no matter. One way or another the side-register mark ends up on the plate.

The question I am posing is "How far back and of what length should the side-register mark be and why?" Just to be clear, I am talking about the line typically a few inches back from the lead edge of the sheet that the pressman sets his press to print, half the line's width on the sheet and half the line's width off the sheet, in order to indicate accurate side registration of the press sheets at the feeder table.

The reason I bring this up is because both the pressmen and prepress staff I've met often believe that the placement of the side-register mark is of no consequence. Obviously I believe that the side-register mark location has a logical placement. So I've started this thread to open the discussion and shine some light into this area I felt was dimly lit.

Of course I'll state how far back I think it should be and why if no one else does it for me.

Best Regards
otherthoughts

 

[Alois Senefelder]

Wow !!!!!!

Wow !!!!!!

WOW, I thought nobody was going to ask !!!!! seeing everyone is "Bogged Down" with " Round v Euclidean Dots" and ink saving GCR software, also TVI !!!!!!!!!!!!
Imposing "Image Control Marks" are " Important " on the Plate

So take a look at these PDFs in answer to the question


Regards, Alois

 

[otherthoughts]

You got my attention Alois/Trevor. There aren't many out there that can conjure up a GATF Technical Report from 1981. Obviously you know your way around a press better than most.

The side-register mark should be as far back as the side register mechanism itself is on the particular press.

Perhaps my original post was a bit on the lame side, but I have met many folks that did not know that one position was any better than another. Even folks running 4 color work on a single color press.

Anyways, I was just trying to help and at least it gave you something to do

Best Regards
otherthoughts

 

[DavidMa]

back in the day, we would put our side guide marks about 3.5 - 4 inches up from the gripper.
The measurement wasn't critical. it was just where the pressmen could see it without it being obscured by the chain or wire on the press as the sheets were dropped on the skid.