Pre-cut paper, inconsistent size, registration hell

[Dog on Fire]

I have been having major issues with ordering pre-cut paper and having inconsistent paper size. Some sheets will differ by up to an eight of an inch or so. I have had this happen twice ordering 19x25 sheets from french and more recently with 400 sheets of 18x24 from a local paper supplier. I will set up registration to a sheet from the pack and about a quarter of the way through printing the paper won't fit within my registration guides. I rack the paper at least 24 hours before printing to adjust to the climate of my shop and use credit card pieces taped down at every corner of the paper. I just finished a job and had to re-register 5 times on the last color due to paper randomly not fitting within my registration tabs. I assume this has something to do with large paper cutters cutting huge stacks at a time by the supplier but has anyone else come across this issue and found a solution? thanks a lot guys.
PS I am renewing my premium membership next payday cause I'm broke as hell right now.

[Steph Nitro]

This shouldn't be an issue if you register only on 2 sides. I put registration tabs on the right edge and on the bottom edge only and nudge the paper up to those, then no matter what variance you get in the paper those will be constant. this is also good for cutting later as the registered edges serve as guides when cutting them down to size.
something an old printer got me onto years ago was to make reg marks that go right up to the edge of the paper on those 2 sides. that way you see immediately if you failed to nudge the paper up correctly to the reg tabs, something which can happen when doing those repetetive large runs.

steph

[Steph Nitro]

Capeeshi?

[Dog on Fire]

thanks for the tip! i think thats the issue, putting tabs on all sides requires the cuts to be exact for each sheet. I'll try your suggestion and try the right and bottom edge only. Ever any issues with diagonal cuts? I have had situations where i have two registration tabs on an edge and all of a sudden certain sheets only line up to one of the tabs and there is a gap at the other. I am assuming this is from an slanted cut? That registration mark to the edge of the print is a great idea as well. thanks!

[Steph Nitro]

cheers. glad i could pitch in with something useful for once I have the longest paper edge along the bottom as i have a one armed bandit print-table where the squeegee goes sideways from left to right or vice versa.... therefore i keep the tabs on the bottom edge as far apart as is practical and on the side edge i only have one, close to the corner, this is all you need to keep the x & y axis constant. I know it sounds weird, when i started i thought the more tabs the bomb-proofer, alas it actually tends to stuff things up and prevents you from having true constants which is what registration is really all about.

[ittybittypress]

Also, if you have your paper cut before you print on it, you should register to the milled edges. You can usually look at a the side of a stack of cut paper and see which sides have been cut.

[Andymac]

if you follow Steph's idea - 2 guides on the long side, and a guide at the one corner, your paper will register the same no matter if it is cut stupid.

Paper is inconsistent, very rarely the size it says.

ON high speeed automatic screen presses with disappearing guides, the guides are actually very small pins, so the contact point is real small - BUT (and this is important) they are always in the same spot relative to each paper. Always mark the location of your guides on the first setup sheet, and relocate your guides for each successive colour in the same spot, especially if the sheets are inconsistently cut, or deckled edge.

[andydiesel]

I don't know who the hell all you people are or where or who taught you how to screen print but it is best to register on all seven sides of the paper.

[Dog on Fire]

Thanks for all the input! Hopefully things will go much smoother tomorrow! I never thought of marking the contact point and keeping it consistent for each color. that is genius! sure that plays a huge factor in the issues i have been having.

[edwardo_machino]

I don't know who the hell all you people are or where or who taught you how to screen print but it is best to register on all seven sides of the paper.

I did this and a geometry rift opened up on my printing table. I gazed into the maw of it and saw a little dog writing equations on a chalkboard.