Guidance on a matte spot varnish for text only

[Davino]

As a book designer, this will be a first time having to use a matte spot varnish applied to just text only. The UV LED offset printing process led to an unanticipated gloss/glare, and though we're keeping this glossier, saturated look for the photos where it's pleasing, it has to be eliminated on all text (a dense scholarly edition where shiny text is a hindrance to reading).

I'm putting together the InDesign file/pdf for this to be applied solely to text, which has both K body text and numerous sidenote annotations by scholars in wide margins that are printed as a dedicated pms spot in a special gray Pantone mix. All text needs to go as flat and matte as possible - exactly as the project was designed when expecting the typical result of printing on matte coated Arctic Volume White stock, conventional offset. We simply didn't know - and the printer did not flag - that UV LED means glossy results.

They're charging $1200 for 1 single sheet as a press proof testing this, adding they've never done this before so we must bear the risk. And is there a distinction between text "overprint varnish" (OPV) and text spot varnish? Both terms seem in use for this, but out printer uses the latter.

All input/comments greatly appreciated. Thank you.

 

[SteveSuffRIT]

Are you questioning the use of terms, the price, or the purpose of the press proof?
I would make sure they print a color bar of just the clear spot varnish so it can be evaluated.
For other readers, there have been other posts about this topic before.

 

[printerdan]

The $1200 reflects the printers desire to end the business relationship.

 

[Davino]

Are you questioning the use of terms, the price, or the purpose of the press proof?
I would make sure they print a color bar of just the clear spot varnish so it can be evaluated.
For other readers, there have been other posts about this topic before.

Forums need questions to be specific, and not freighted with overlapping concerns, so I apologize. The central concern is executing matte OPV on text only, well. Here's the Adobe InDesign forum's advice - do the print experts here concur?

"1. Registration spread: Ask the printer about spreading the varnish plate by ~0.05mm so the matte slightly overlaps the text edges. A matte halo is less distracting than a gloss sliver.
2. 100% tint only: Never reduce the varnish percentage. A halftone screen on the varnish plate creates grainy, mottled text. Solid blanket coverage only.
3. Overprint verification: Check Separations Preview in Acrobat Pro to confirm the varnish layer is set to overprint, not knockout. A physical test spread through the printer's RIP on the actual stock before the full run is the ultimate confirmation."

Claude A.I. offers: "Some printers prefer to control the spread at the RIP as they know their press's registration tolerance precisely and can apply the correct spread value there. Others prefer it built into the file." That's the detail-level input sought: build it into the varnish file by adding ~0.15 pt. stroke on text, or is it best for the printer to handle the spread?

 

[SteveSuffRIT]

You need to pay for a single form press proof to "see" the final production results of matte spot varnish over teh text only. Yes, of course, the matte varnish plate needs to be spread fatter to allow for misregistration.

 

[Davino]

You need to pay for a single form press proof to "see" the final production results of matte spot varnish over the text only. Yes, of course, the matte varnish plate needs to be spread fatter to allow for misregistration.

Spread fatter in the file the printer receives from us via increasing stroke on the letterforms for the varnish layer, or is this handled by the printer normally? The latter, I believe, but just to confirm.

 

[SteveSuffRIT]

Yes, let the printer apply their "spread" trap value at the CtP RIP.

 

[Davino]

Yes, let the printer apply their "spread" trap value at the CtP RIP.

The printer is having us create the varnish file with a 0.05 mm spread as opposed to them applying a spread trap value at the CtP RIP. It's a separate file in 100% K that they use for the varnish, according to their method. I imagine there are different means to arrive at the same end, but given they've said "we've never done this before," they may not be as versed in what's best. In the future, any text change requires updating the matte OPV file too.

The added complexity and cost of matte varnish on text keeps me up at night, but I’ve reviewed the prior test print under all lighting conditions, with widely varying results. Under flat, even lighting (e.g., in the modern Singapore subway tonight, cool color temp LEDs), it’s less bothersome; one suddenly wonders if this intervention is necessary. Then, in contrast, under a multipoint lighting situation (under dangling pendants, halogen color, well and adequately lit overall, but dynamic, not flat), the glare was an unmitigated disaster, utterly unacceptable, a night-and-day difference.

We’re moving ahead but may also let them run a sheet on Sappi Magno Volume in addition to the Arctic Volume White, with a portion of the Magno unvarnished just to verify if the glare is still as prominent. UV LED ink shine on text, on bright white Arctic stock, is a 1-2 punch to the eye where matte text would, otherwise, be ok. Magno may make no difference in terms of shine, but it's a less bright stock, less contrast, and may also reveal what their process does to Magno's natural texture. Recall it altered Arctic's (covered earlier).