I’ve “G7’d" a few UV offset presses and their behavior is not all that different than normal offset. Some things to consider: Ink chroma is down a little from typical offset inks. As I recall, yellow chroma/density was a bit less and black ink density especially was lower than typical coated offset. I recall black density on coated papers to be around 1.50-1.60 or about -.20 from non-UV inks. for this reason, SWOP colorimetry works better than GRACoL on coated papers. Where the curing lamps are positioned makes a big difference in the overprint colorimetry. Interdeck curing results in a “dry” trap between units. If you want ink trap behavior more typical of offset inks, wet trap between the units and don’t cure until the last ink goes down. If you wet trap, you’ll get overprint colorimetry closer to GRACoL/SWOP/FOGRA. In my opinion, the best use of UV-cure offset inks is on uncoated papers where you can use a much higher ink film thickness without having ink drying issues. Also, the rather flat/matte look of UV inks doesn’t look so bad on matte uncoated papers. When printing on gloss coated papers, the gloss differential of the inks is pretty noticeable unless you post-coat. My 360-390nm worth. :-) Terry

On Dec 8, 2017, at 4:20 PM, Roger Breton <graxx@videotron.ca> wrote:

Scott,

"UV Offset" and/or "UV Hybrid" inks, such as those used in sheetfed offset lithography, 40" Heidelgerg, Komori, Mitsubishi, Roland, KBA presses, to my humble knowledge, are formulated with a photo-initiator such that they instantly dry when illuminated by a light source containing certain wavelengths of light, in the UV range, such as 360nm. I'm not sure if it's that exact wavelength, though.

I confess I have not personally seen much "UV curable inkjet printing" in my young carreer. Please excuse my ignorance but where have you seen them being used?

Is that what Mike was referring to? Sorry I missed that entirely.

Best / Roger

-----Original Message----- From: Colorsync-users [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com <mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com>] On Behalf Of Scott Martin Sent: Friday, December 8, 2017 9:11 AM To: colorsync-users <colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com>> Subject: Re: Colorsync-users Digest, Vol 14, Issue 57

I see! Mike is asking about UV offset, not UV curable inkjet printing...

Scott Martin www.on-sight.com <http://www.on-sight.com/>

...

On Dec 7, 2017, at 3:51 PM, Roger Breton <graxx@videotron.ca <mailto:graxx@videotron.ca>> wrote:

Good points, Paul.

I have personaly seen many sheetfed presses running UV inks hitting pretty much the same Lab colorimetry on their process color inks than with conventional inks.

/ Roger

-----Original Message----- From: Colorsync-users [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Paul Sherfield Sent: Thursday, December 7, 2017 7:16 AM To: colorsync-users@lists.apple.com Subject: Re: Colorsync-users Digest, Vol 14, Issue 57

Hi Mike

If the UV offset inks match ISO 2846 then the standard Fogra 39/51/47/52 or G7 based profiles can be used as normal for proof simulation and process control on press.

Regards

Paul Sherfield

The Missing Horse Consultancy Ltd

07899 906385

http://www.missinghorsecons.co.uk

Follow us on: Twitter.com/missinghorse

Member - UK TC130 Technical Advisory Group (ISO 12647 Printing Standards) Chair - BPIF Colour Quality Scheme certification steering group UK Representative-ISO TC130- WG13 for printing standards certification

...

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On Dec 8, 2017, at 3:20 PM, Roger Breton <graxx@videotron.ca> wrote:

Scott, I confess I have not personally seen much "UV curable inkjet printing" in my young carreer. Please excuse my ignorance but where have you seen them being used?

Hey Roger. I’ve been working with UV Curable “inkjet” printers at client sites for over 17 years. The likes from Vutek, Oce Arizona, Jeti, Agfa, Durst, Vanguard and others. These machines can have a high price tag (some are near a million US$) but are very affordable to run with cheap inks, materials and fast speeds which translate into high productivity. They are the top dog option for signage printing but the quality has gotten good enough recently for fine art work. Of course the ability to print on nearly everything including metal and glass is an advantage. I’ve seen people take their wood fence sections and car hoods and throw them in these printers. I have a video of a Vutek 100Pro in action at https://vimeo.com/91924432 <https://vimeo.com/91924432> I focus more on the high end large format printing market rather than offset printing. I didn’t get it that Mike was asking about UV offset pritning though - my mistake. Fun to see this technology make it to offset. FWIW, all of the large format printers we work with today (solvent, latex, aqueous, UV, etc) use the same type of pigments. But these pigments start life in powder form and can't be delivered to the page easily without a liquid “vehicle”. So our desktop inkjet printers use an aqueous vehicle, and are therefore more accurately called “aqueous printers”. These UV Curable printers use a UV curing liquid vehicle, solvent printers a solvent vehicle, etc. At least that's how Epson head engineer uncharge of ink explained it to me... It’s also worth saying that there are UV liquid lamination machines that use a clear UV “ink” to coat prints with an unusually durable coating. As a bonus, this enhances the DMax and saturation of the inks underneath (which UV inks historically need). Scott Martin www.on-sight.com