Matte UV-ink for offset

[Davino]

The gripper marks I noticed earlier. Here are a few photos of ink applied with a heavy roller ball pen, piled up to a bit of a bead and absorbing as I took pics, both in the gripper area (left) and the printed area (right). Under a loupe, I'm not seeing a difference, but may be missing it.

Without any other explanation evident, it seems that the printed ink alone is giving the impression of a different surface across the whole page somehow, and, of course, a larger sheet bends/drapes/moves differently than an A4 sample. The only other conceivable explanation for that difference in the virgin areas of the scatter proof vs. the Arctic A4 samples would have to be (and I'm dubious) an effect of UV light exposure on the substrate, or something else about the handling at the press (i.e., press pressure/heat changes the paper surface across the whole sheet, or paper conditioning before printing creates differences). Is that possible?
.
No responses from TOYO today in all my weekend inquiries across Europe and Japan (4 in total). If we can't obtain matte ink, pre-mixed from TOYO or custom, then advocating for the spot dull varnish on letterforms is the only option left.

 

[SteveSuffRIT]

This photo shows a single line drawn across boundary of gripper bite margin to left (which is ALWAYS virgin and UNcoated) vs. where coating was applied to right side.
Must be done with water based markers, NOT solvent based.
Coating acts as a sealant, causing ink to bead up into droplets.
At this scant angle, you can see some of the gloss difference with & without coating.

 

[Davino]

Yes, this is exactly what I was picturing. The rollerball ink I used - and I've now drawn lines across the gripper demarcation into the print area - is a water-based not solvent-based type of ink. And again, the stock itself has a light coating direct from the supplier - it's a coated stock - but not an AQ or other finish applied by the printer, which the test confirmed it seems.

As I say, the only other conceivable explanation for the difference in the unprinted areas of the proof vs. the Arctic Vol. White A4 samples I have would have to be an effect of UV light exposure on the substrate, or something else about the handling at the press, such as press pressure/heat changes across the whole sheet, or other sheet conditioning. Is that at all possible?

 

[SteveSuffRIT]

Hi Davinio,

I don't think the paper is changing its physical surface characteristics from exposure to UV lights, pressure or heat.
Can you send more photos of what your concern is?
When you say "proof" do you mean a prepress digital proof (Epson, HP) or do you mean an actual printed press proof using real ink and paper on press?

 

[Davino]

Wet proof (technically a scatter wet proof), not an Epson or otherwise. It was several 900mm x 640mm sheets for $1400USD. I'm supplying more photos here, but it's difficult to convey how any stock feels different in photos. It's not a color change and close ups don't really show any surface texture difference. It is, however, the plasticky feel to the UV ink that mostly may be inducing this perception. I say "inducing" an "impression" because although the we clearly can feel the inked areas, it lends the whole sheet - even the virgin areas - the sense that it's another stock with different properties.

Just made a half dozen phone calls to TOYO Ink branches in the EU, abandoning the email route, and at the end, spoke with an older gentleman in the Netherlands with decades of experience as a printer before working for TOYO. His response was telling. Like forum members here, he understands and was sympathetic to the text glare issue of UV LED cured ink but noted that in all his years at TOYO, this was the first instance of a client making this point that he has ever come across. He's going to speak with colleagues to see if it's possible to arrange the matting agent for us and perhaps some tests. If I'm going through this much trouble, then the matte effect should be for both our body text and the hundreds of sidenote annotations that are in a custom mix Pantone gray (cool or warm 10C mixed with 9C), all printed as a spot ink. Nothing beats person-to-person contact where we register details that are otherwise lost in anonymous emails.

I don't wish to irritate the printer - we are partners and have collaborated thus far for many months on this. But I'm not letting the goal suffer. We're getting matte text via addition of a matting agent to the spot text ink or via a spot matte varnish to letterforms only, and a test to demonstrate this successfully is reasonable, which will be funded. Hopefully not as expensive if just doing a sheet of text.

 

[SteveSuffRIT]

UV ink cures to a 100% solid, unlike oil based conventional inks that contain both solvents that evaporate/absorb and oils that oxidize and polymerize.
UV inks cure instantly, so their wet ink film thickness (IFT) is the same as their dry ink film thickness. UV ink sits on the top surface without any absorption into the paper. You may "feel" UV ink, similar to digital toner from xerography/electrophotography or screen or thermography.
Your initial concern was with the orange-peel glare appearance of the type distracting and tiring the reader. Now it sounds like it's about tactile feel, a completely different issue!
Is this your first time experience with UV printing? Perhaps your expectations are based on conventional inks?

 

[Davino]

UV ink cures to a 100% solid, unlike oil based conventional inks that contain both solvents that evaporate/absorb and oils that oxidize and polymerize.
UV inks cure instantly, so their wet ink film thickness (IFT) is the same as their dry ink film thickness. UV ink sits on the top surface without any absorption into the paper. You may "feel" UV ink, similar to digital toner from xerography/electrophotography or screen or thermography.
Your initial concern was with the orange-peel glare appearance of the type distracting and tiring the reader. Now it sounds like it's about tactile feel, a completely different issue!
Is this your first time experience with UV printing? Perhaps your expectations are based on conventional inks?

The issues are interrelated but the primary concern is indeed the glare to the type, yes. We were taken aback by the wet proof's characteristics on the chosen stock with UV printing - the images printed better than expected and the type worse, and the total effect on this stock (chosen for its low glare and tactile qualities) compared to its A4 stock samples made an altogether different impression. UV printing seemed to transform the stock's character across the full sheet, but this is all due to how UV printing is, it seems. It's our first time with UV and we're pleased with the image quality, even with glare, but solid, flat, matte text is essential for a difficult, long scholarly text.

 

[Davino]

The Baltic region TOYO Ink branch is saying TOYO hasn't had matte inks in 6 years. The US branch says they have the matting agent to add to inks, but shipping ban lists may prohibit sending to the EU. Baltic TOYO claims they inquired around the EU and UK for leftover matte ink but none is available, and the min. quantity order for a new batch is 800kg, far from feasible for one book. The Dutch branch, separately, is sympathetic and looking for leftover supply of matte ink in the EU as well.

Baltic TOYO says that a matte additive in powder form can't be mixed properly by the printer as offset inks are too viscous and we won't get proper dispersion. They suggest instead that we "try" adding matte varnish to the ink to "reduce" (she did not say "eliminate") the gloss. But this sounds like risking possible dilution of the depth and color saturation to the ink.

Do any of us here know whether powder matting agent (if it only exists in powdered form, not liquid) can be added to finished inks by the printer, or can this only be done during ink manufacturing with the necessary equipment?

The matting agent the US TOYO branch refers to is Evonik's ACEMATT OK 412.

[UPDATE] The French TOYO branch indicates they'll handle a min. quantity order of special formulations as low as 1kg. This would solve the matter if we can cooperate with them. Later spoke directly with Toyo France on the phone, and they've bounced it back to Toyo Belgium saying only they could custom batch it, with whom I spoke earlier and was waiting on the results of their search for leftover supply. I've re-emailed them to clarify if a custom small batch can be made.

 

[Davino]

Received call from Toyo Belgium head of sales for the EU. Potentially the end of the line. He grasps all the conditions involved now and will review the possibility of a custom batch of matte far below a previously stated MOQ of 800kg. He says that when their matte ink was discontinued years ago it was because the UV formulation was producing inconsistent results across different paper stocks, with printers dissatisfied. Also encouraged our printer pursue separate text plates to apply matte varnish to the text letterforms only, which our printer has not been responsive to. A decision on a custom matte batch is promised by tomorrow.

 

[Davino]

Apologies for the incorrect use of the term "strike-through" earlier in reference to matte varnish on letterforms - I've edited it out. I believe the correct phrase/terminology is a "spot matte overprint varnish on letterforms only" as the alternative to matte text ink.

Toyo Ink has not said that Arctic Volume White is one of the stocks that their matte UV ink formulation worked problematically with.