Overprint varnish on digital print?

[pressmanken]

We printed cards for a customer on our Minolta color machine that cracked when they were scored and folded. I have an idea of reprinting digitally again and overprint varnishing on the offset press to avoid completely redesigning the job as a strictly offset design. Will this work, or are there problems with this that I'm not seeing. The customer loves the digital print look of his cards, and I'm sure he wants to avoid the extra expense of printing the entire job on the offset press. I'm in a bit of a rush for an answer, as he is expecting some resolution plan today. I appreciate any insight anyone can offer on this.

[che.c]

Creasing them properly (rise and fall with a proper creaser bar) will reduce the cracking a lot. Scoring doesn't really work on digital.

Alternatively (if the run's small, still cheaper than sending them litho) you could laminate them which would also get rid of the cracking. Though that will change the nice digital finish that yer customer likes. Still, if it's the glossiness he likes, then I'm sure gloss lamination would go down a treat! Just make sure you get someone who knows what they're doing or the laminate will peel off...

[effeegee]

No easy answer for a toner based machine where ink coverage is significant
A. Scoring with a rule will reduce cracking but almost certainly not eliminate cracking on toner in the fold unless it is light coverage.
B. Overprint varnish will be difficult too - unless it is clear toner applied as part of printing. The release oils will tend to stop varnish adhering whether microencapsulated in the toner or applied with rollers in the non-image areas (depends on the fusing type)
C. UV varnish or laminate with appropriate varnish/ laminate may be successful but watch out for laminate releasing after a while - through release oil migration etc. Test first.

[pressmanken]

Looks like it's a press job, after all. Thanks again for the feedback.

[Craig]

Just crease them, we do it all the time on full cover fold.

[Emtri]

It would always help to get some paper that is the opposite grain direction to whatever your currently running. this will also greatly decrease cracking on folded sheets.

[pressmanken]

They were creased on a Count EZ Creaser, and it doesn't look like grain direction has any effect on cracking. Going to look at laminating, but as they are foldover BCs, that may not work either. I'm on the tail end of this, trying to offer a solution. I think they are a bad design as printed, and offset will work better for this job.

[Craig]

Is the score in the right direction? If it looks like it is backwards it correct. In other words if you are bending it down the score should look like a U, so it will hinge up. We crease (not an impact score) every thing that is folded if it is printed digitally. We never have a problem with cracking, even on solid rich blacks.

Many times you will see cracking, especially on coated stocks. It's not the ink or toner cracking, but the stock itself. Try plain stock and see if it cracks as well.

[billyinlasvegas]

I print digital all day and your problem might be cheap paper.

My secret to no cracking is use good paper, crease and go with the grain.

Also I've upgraded from a Count creaser to a Morgana and the results are amazing on any paper weight.

[Happyprinter]

We have one job that we do digitally on our Ricoh 901 and then varnish on our QMDI. Never had a problem. It is a short run, smaller presentation folder that we cannot run thru our UV as the glue will not bind properly to the UV. Varnishing has been very easy and the results look great. Our customer is very happy with the end product. And best of all, no cracking! All the other advice given so far are possible solutions, but if you cannot get it to work, use the varnish, it works great..