Professional Photography : gloss enhancer

Why Add a Finish to Your Prints?

Eileen Fritsch — Mon, 02 Nov 2009 13:09:00 GMT

I’ve long felt conflicted about finishing my prints. When I first tried it years ago, most of the products available used smelly, potentially toxic chemicals. I didn’t have time to experiment with some of the creative effects that could be achieved with gels and I was skeptical that a spray or liquid clearcoat could add to the archival life of a print.

Those days are gone. Today there are many non-toxic/non-hazardous sprays and liquids that can applied to protect the entire print surface as well as gels that can be applied either to the whole print or selected areas of the print for artistic effects. Plus, independent testing groups such as Wilhelm Imaging Research have shown that products such as Premier Eco Print Shield can extend the display life of a print.

Finishing products can be applied with a spray gun, roller, brush, and even one’s fingers!

What are some of the reasons one would want finish a print?

Protection of Print Before They Are Framed. Even if a print will ultimately be framed and displayed behind glass, a good, evenly applied spray can protect the print from the accidental scuffing, scratching, fingerprints, or sneeze-damage that can occur as the print is handled and packed up for transport from your studio.

Protection of Unframed Prints. Some photographers and artists regard the glass or acrylic used with frames as a barrier to accurately viewing all of the colors and details in their work. And canvas is typically displayed unframed or framed without glass, so the viewer can fully appreciate the subtle textured weave of the canvas.

Any print that is framed without glass needs to be protected, not only from UV light and abrasion, but also from airborne contaminants such as cooking fumes, cigarette smoke, and insect residue. Printed canvas that will be stretched to create a gallery wrap needs to be protected from the abrasion that can occur while the print is being stretched. Even inkjet-printed pages that will be bound into an album or portfolio book need protection as the pages will be frequently touched and turned.

Appearance. Some sprays can change the appearance of an inkjet print to better resemble continuous tone printing, by reducing or eliminating gloss differential and bronzing. The gloss optimizer used during printing with the HP Designjet Z-series printers greatly reduces or eliminates these problems, but many enthusiasts and professionals who use printers without gloss optimizers have discovered that the right spray can even out the gloss on a print surface.

Artistic Effects. Some photographers and artists now use different types of gels and varnishes to embellish their prints before they are matted and framed. These gels can either subdue or enhance overall contrast and color or add texture or brushstrokes.

Perceived Value. If done well, print finishing may make a print more attractive to a potential buyer or collector. Hand-embellishing a print by brushing on a gel makes each print a unique piece of art.

Frequently Asked Questions about the Gloss Enhancer on HP's Designjet Z3100

BlogArchive — Fri, 21 Sep 2007 13:22:00 GMT

By David Saffir

Any time a pro-model inkjet printer comes out with features radically different from the status quo, questions inevitably arise from photographers anxious to fully understand the true capabilities and benefits of the new features. That’s certainly been the case with the Gloss Enhancer on HP’s Designjet Z3100. Here are just a few of the questions I’ve been asked at some of the trade shows and seminars I’ve attended.

What is the HP gloss enhancer?

It is a clear ink, which when mixed in correct proportions with the other inks on the page, provides a more uniform gloss on the surface of a print, effectively eliminating gloss differential on prints created on glossy or satin papers, and perceived “bronzing” in black and white prints.

Which media can the gloss enhancer be used with?

The gloss enhancer is intended for use on glossy and satin inkjet media. It has no perceptible impact on fine art, watercolor, and similar matte papers.

Is the gloss enhancer like a clear coat or varnish?

No, it is not a clear coat or varnish. The gloss enhancer’s main purpose is to improve the smoothness and gloss appearance of the final print. In my opinion, the gloss enhancer renders prints made on glossy or satin media as smooth and uniform as their darkroom cousins. Personally, I find that the dimensionality and “pop” of the prints is improved, and I find it very pleasing.

Unlike a clearcoat, the gloss enhancer is applied like an ink, and is closely controlled by software. In fact, the gloss enhancer is controlled by its own screening algorithm and it is applied selectively where it is needed. The gloss enhancer is only applied to areas of an image that have an RGB color value of 254,254,254 or lower. Pure white (which has RGB values of 255 in each channel) will not receive the gloss enhancer. (As a practical matter, I set white and black points slightly under max values when using inkjet printers.)

How do I control the use of the gloss enhancer when printing?

The printer driver provides controls that allow you to either: (1) turn the gloss enhancer off; (2) use it only on the inked area (“econo mode”); or (3) use it on the entire page. I recommend turning the gloss enhancer off for making proofs, and using the econo mode for final prints. Applying it to the whole page is usually unnecessary, and wastes a small amount of the enhancer.

What effect does the gloss enhancer have on color?

That’s a good question! If you look closely at a print that has been made using the “whole page” setting for the gloss enhancer, you may perceive a slight change in the white point of the uninked paper. In other words, you will see the gloss enhancer on the unlinked portions of the page, and it seems to reduce the white point to a very small degree. I’m not certain, but I believe that this is the result of increased “glossiness” or reflectance.

In my conversations with HP color scientists and engineers, they indicated that the gloss enhancer has no effect on color rendering in a print. In my own experience, I have made prints from the same color image using gloss enhancer turned on, and turned off – and I can’t discern any significant difference in color between them. Gloss appearance and smoothness – yes; color change – no.

Does use of the gloss enhancer change the dry time for a print?

Not in any significant degree, at least on HP media. Some users tell me they have noticed increased dry times when using third-party media. I use many types of papers, but I haven’t had this problem. I suspect some of these issues may be related to using printer-managed color with third-party media, instead of creating a custom profile for the job at hand.

Does use of the gloss enhancer improve print durability?

I don’t have hard information on this topic. First, on HP media the prints are highly water and damage resistant --even without the gloss enhancer. Prints made with HP Vivera inks are highly water resistant, even under running water. Using the gloss enhancer, my personal impression is that prints seem to be more water and scratch-resistant, but I’m not sure how one would go about quantifiably measuring these properties.

Does it make sense for photographers to use the gloss enhancer?

In a word, yes. I see little or no downside, and the benefits in terms of print appearance are significant. I use it consistently. I recommend it to all of my printmaking customers, and so far, none have told me that they prefer not to use it.

In my opinion, the HP Professional Satin photo paper combined with the Z3100 Vivera inkset (including gloss enhancer) provide the best-quality pigment-based photographic prints I have ever seen.

If you have tried the gloss enhancer, I’d be interested in hearing more about your own experiences and observations. And if you have any other questions about it, please feel free to ask.

The Power of Black and White

BlogArchive — Fri, 20 Jul 2007 13:53:00 GMT

By Jon Canfield

I find it ironic that black and white imagery seems more popular than ever in the digital age. There’s just something about a strong monochromatic image that is more compelling than anything you can create with color. But obtaining a quality black and white from an inkjet printer has been frustrating, with many prints showing a color cast or significant bronzing.

While monochrome inksets are available from vendors such as MediaStreet, Jon Cone’s Inkjet Mall, and Lyson (yes, there are others, but these three have been the top-quality inks in my experience), new printers such the HP Designjet Z3100 have reduced or eliminated the need to go with a pure black and white printer. Obviously, not having a dedicated black and white printer saves money and space, but is the quality from the HP Designjet Z3100 really that good?

To find out, I made some comparison prints using this black-and-white image. For neutral tones, the HP printer was a clear winner with better tonal gradation and more neutral grays. Only when I went to a toned print did the dedicated inks show any advantage at all.

One area in which the other printers and inks couldn’t compete was the use of the gloss enhancer available on the Z3100. When printing to fiber or gloss media, the addition of gloss enhancer made a dramatic improvement, eliminating bronzing from the final print.

Part of the reason for HP’s high quality is that you’re essentially printing to a quadtone printer when using fine art media. The Z3100 uses both photo black and matte black along with the two grays. By not using any of the color inks, you eliminate any color cast that may otherwise be present. The only way to accomplish this with other printers is to replace the inkset with a dedicated monochrome inkset. This is costly and impractical when you also want to print color because you need to flush the ink lines with every cartridge change.