How solid can varnish be tinted?

[ReflexBlueHorror]

Hello, I'm a new member and this is my first topic post. I've spent a lot of time reading these forums to aid my print education, thanks everyone.

I've read in regards to offset printing and varnishes that 1) varnishes can be tinted with pigment, and 2) varnishes, applied via a plate, can achieve fine details and registration than aqueous and UV.

My question is, how solid can the varnish be tinted? Could it, say, become a rich glossy black?

The substrate is uncoated paper (Munken Pure) and, according to the mill's guides, could have an aqueous flood and then successful spot UV (2 coatings).

The only other ways I know of creating a glossy black ink effect would be black pigment foil (cost prohibitive and easily worn), thermography (but can't be double-sided), and reticulating/drip-off/strike-thru varnish (not sure how successful this would be even if the AQ flood serves as a primer before the matt varnish plate). I've always found spot uv to have trapping and registration issues, and so shouldn't be combined with black body text. But I'm thinking that if the varnish was tinted - spot varnish or spot uv - it wouldn't need to register to anything beneath.

 

[SteveSuffRIT]

I think it will be very difficult to obtain a glossy apperance on an uncoated offset sheet with a VARNISH becasue the paper's base surface text is too rough. A varnish is applied like an ink thru a roller train so its ink film thicknes (IFT) will be too thin (~1um) to fill in the deep valleys.
Coatings, either warter base (WB), aqueous (AQ), or ultraviolet (UV), are applied from an flexo style anilox roll that transfer and apply a much thicker weight. Cell volumn is measured in BCM (billion cubic microns). Coating weight is pounds/thousand feet squared. Also, UV is 100% solids so dry = wet weight. AQ/WB evaporate off their VOC.
If I recall correctly, black ink is usually about 20% pigment load and the remaining 80% balance is vehicle or varnish. A 'perfector" black ink needs a thinner IFT to prevent back cylinder piling so has a higher pigment load.
Steve Suffoletto

 

[ReflexBlueHorror]

Thanks Steve. I fell into the young designer's trap of getting confused between varnishes and coatings.

By your answer, are you saying that WB, AQ or UV can be tinted?

Most Spot UV artwork guidelines I've collected advise a tolerance of 1mm misregistration and fill-in for reverses lower than 1 pt. I'm guessing that's partly from the thicker application, and otherwise from being done offline.

 

[SteveSuffRIT]

If the spot is being done as a varnish with a litho late, register is the same as any other ink color, ~0.004".
If the spot is being done with a coater, using a photopolymer relief plate (flexo), then the tolerance is not as exact!
One factor is the relief plate distorts around the cylinder and prepress needs to compensate for this longer length, the width is usually fine.
Inline process is best register fit becasue offline needs a separate pass and you don't have to worry about mecahnnical press register (infeed gripper and side guide) or paper distortion.
Steve Suffoletto

 

[ReflexBlueHorror]

Perhaps the question I should've asked was how solid can a Spot UV be tinted with pigment?

 

[turbotom1052]

There is a limit to just how thick of a film can be layed down. Doesn't matter if its an Aqueos coating, a UV coating , or a press unit applied varnish. When you factor in SAFE film thickness, and when I say SAFE I refer to its ability seal, cover, and dry without blocking or setoff then you can see that your limits to "tint" are going to result in not very rich colors. My guess is that your trying to cheat a little, and get color AND sealing properties from the same unit. If in fact you are then id suggest you don't tempt fate!!! Lay the color down on a dedicated unit and let the coater or varnish unit do what is designed to do.