gloss spot varnish HELP

[turbotom1052]

@turbotom1052 Though probably not feasible with our own equipment (graphtec plotter and an esko router cutter), I would be interested to see how precise a CAD plotter could get.

If your looking for the sort of registration that an imaged varnish plate can offer, then I would say forget it. If your content with getting accuracy within 1 millimeter, then thats achievable.

 

[Qbot]

I am a printer in northern California in the San Jose area (there are very very few of us left here) We had a job on 24 pt board that required a spot varnish over a matte coating (they actually had us run it through again to make the varnish stand out) I have been in this industry for very close to 50 years and my foreman has just about the same amount of time in the industry also, we ran the two passes in lifts of about 300 sheets and we winded it within a hour. We both voiced our concern about this job believing that for the sheen they were looking for it should be sent out to uv coat because even at small loads and winding about 25percent were sticking. Well to our surprise they took this job on in huge quantities for sheetfed presses (one hundred thousand to three hundred thousand) We have a meeting tomorrow and before I tell them they are out of there *&^%$%^ minds I want to know if anyone out there maybe has some experience with this huge amount of spot varnishing and could give some suggestions. Any info would help or reassurance that we are correct and this job is completely unpractical would be so appreciated... This is a 5 color job (4color process and one pms with a matte coating) printing on a 6color Mitsubishi with a conventional roll coater

Anybody out there cut a litho printing blanket on a zund or kongsberg cutter? Pretty sure it can be done. Cut file probably needs to be mirrored. Anybody have a workflow for this? Thanks, Tim

 

[Chicago Joe]

Run it as slow as you can and let the sheet float into the delivery end. And alch to the water, run the water tight.
You should see the plate lightly scumming in the non-image areas. Switch to a heavier grain spray powder, and super small loads.
And this is why adding a UV drier to your press is great if you can swing it.

 

[Magnus59]

@turbotom1052 Though probably not feasible with our own equipment (graphtec plotter and an esko router cutter), I would be interested to see how precise a CAD plotter could get.

You would need to calculate the circumferential increase in print length when the blanket is mounted, we used to do this with rubber stereos for continuous stationery printing, setting type in hot metal with the appropriate reduction scale, pressing onto a flong, then transferring to a rubber plate to mount to the press. It was a different calculation depending on whether we were mounting to a 17" or 22" cylinder.