Spot dull varnish combined with spot UV

[gig0]

Suppose you have to print a checkerbord and your customer wants all the red squares to have a dull varnish and all the black squares to be UV. They supply artwork that has a spot dull varnish layer along with a layer that has a spot UV. Knowing this is a registration nightmare (because the UV coat will be applied at another facility) would there be any noticeable difference if just an overall dull varnish was used with a spot UV?

I'm in that boat right now except substitute the squares with thousands of images and letters. My mind is telling me the reflective property of the UV has no bearing on quality if a dull varnish is underneath or not. Thanks.

 

[chevalier]

Are you doing this in a one pass method or two pass/offline UV Coating? What you are wanting to do will work but there are caveats. I will elaborate based on your response.

 

[gig0]

one pass then goes to another facility for the UV.

 

[chevalier]

OK for your situation:

• The varnish has to be completely dry prior to UV Coating. If you wet trap you'll end up with a strike-through appearance that may or may not cure.
• The varnish has to be UV overprint compatible. The UV has to be able to adhere to it. Not all varnishes/coatings are created equal. Seek out the vendor who makes the varnish and get documentation that says that it is UV compatible. If not the UV will wipe away somewhere between donut glaze and dry eraser marker.
• The varnish will behave like a primer for the UV to adhere to. You don't need to trap or knockout.

Stated most basically a dull coating/varnish diffuses creating the matte/dull appearance while a gloss coating/varnish reflects causing a glossy appearance. Think of it just like frosting glass. It works both ways: if you dry-trap matte on gloss it will become matte and if you dry-trap gloss on matte it will become gloss. What is underneath does not really matter as long as the top coat can adhere to it and sufficient top coat is applied.

 

[gig0]

B-E-A-UTIFUL! Just as I suspected. Thanks!

 

[chevalier]

I'm deadly serious about making sure the varnish is UV overprint compatible and that this is clearly documented. I was witness to a >$30,000 job rejection because of an incompatibility. The coating vendor provided documentation saying product XYZ123 was overprintable with UV but shipped us product XYZ234 which was not.

 

[gig0]

Just checked with our ink rep and our wax free matte varnish will work. Printed sheets will dry all weekend and off for UV coating on Monday. Potential disaster averted. Thanks again!