Ink

It’s complex chemistry

The science of ink formulation is one of the most significant, if not the most significant, factors driving the current inkjet revolution. Ink is complex chemistry. It’s colorants (dye or pigment varying in type and density), resins (protecting colorants and reduce metamerism), mediums (suspending the colorants), solvents (increasing viscosity to deliver it through tiny nozzles), and drying agents (decreasing drying time and reducing dot gain).

Consider the currently reigning inkset for professional photographic inkjet printing – Epson’s UltraChrome HDR. Epson UltraChrome HDR ink’s exceptional pigment density delivers supersaturated colors and dense blacks unprecedented in photographic output, able to be delivered in small droplet sizes (2-6 picoliters – a picoliter is one billionth of a billionth of a liter), smaller than the width of a human hair, so quick drying that droplets form a precise dot and prints emerge from printers essentially dry, water and ozone resistant pigment is encapsulated to reduce light refraction and abrasion. High Gloss Microcrystal Encapsulation Technology is formulated into the inkset’s suspension technology to make the print surface more uniformly reflective despite dramatic variances in ink density throughout a print. While counteracting the tendency for gloss to reduce as pigment content increases, gloss-optimizing additives also increase translucency allowing higher ink density and chroma.

Epson still leads the inkjet revolution. Recently, there are competitors whose newest solutions and their immanent evolutions deserve serious consideration and monitoring – Canon’s Lucia inkset and HP’s Vivera inkset.

Epson K3 on matte and luster

Dye vs pigment

While there are profound differences between dye-based and pigmented inks, the differences in image quality are frequently overstated and sometimes misstated. Years ago, pigmented inks suffered from reduced gamut (saturation) and dmax (maximum density or black) and increased metamerism. Today the differences lie largely in the areas of longevity and durability, where pigment still reigns supreme. (Cost may also be impacted, as dye inks are typically less expensive to manufacture.)

Multiple inks

To improve gamut and dmax manufacturers have been adding more inks to inksets; alternate colors (variants of offset’s high-fi orange and green, light cyan and magenta, or red, green, and blue) and additional blacks (blacks optimized for matte and glossy surfaces, light and medium blacks or grays) are used in combination with CMYK.

Do more inks yield better image quality? Typically. But not necessarily. Image quality is the result of a combination of a number of factors. To assess print quality, you have to assess the total printing solution – ink, profile, rendering intent, driver, screening algorithm, ink limit and substrate. Compare gamut, dmax, ISO brightness, neutrality, graybalance, metamerism, gloss differential, bronzing, gradation, fine line detail, longevity and durability. Both the physical makeup of ink and its application are important.

Gamut and dmax

The impacts of increased gamut and dmax are both easily seen. Gamut has a dramatic impact on color but not black-and-white print quality – more saturated color. Dmax has a tremendous impact on both color and black-and-white print quality – blacker blacks.

What is not obvious is that greater dmax extends gamut by increasing the saturation of dark colors.

Dmax and gamut figures for inkjet prints are at a photographic all time high. Both significantly exceed traditional print materials. (Dmax – silver gelatin 2.35, Epson UltraChrome HDR 2.45, Canon 2.5.)

Neutrality and graybalance

Inksets with multiple black inks not only deliver the best dmax, they also deliver the best neutrality and graybalance (consistent tint throughout the tonal scale). Producing truly neutral and consistently neutral colors with supersaturated inks is quite challenging; black ink becomes a stabilizing factor. While ink is an essential factor, it is not the only factor – driver’s and profiles play a significant role.

Highlight detail

Light inks, including light black inks, aid in the reproduction of highlight detail. They hold detail with not just smaller but also less visible dots.

Metamerism 

 Metamerism can be reduced with multiple black inks and heavier black plate generations (using more black ink to reproduce the image). Metamerism can be minimized by reducing the use more metameric saturated inks and increasing the use of less metameric neutral inks. Metamerism can also be subdued by coating irregularly shaped pigment particles with polymers, making surfaces more uniform and reducing light refraction. 

Gloss differential 

Gloss differential is an uneven sheen due to varying ink densities in highlights and shadows that affects glossy surfaces significantly more than matte surfaces. Gloss optimizing additives are incorporated into ink formulation to dramatically reduce gloss differential. It goes where ink doesn’t. It also counteracts the tendency for gloss to reduce as pigment content increases. It goes where ink doesn’t.

Sprays, coatings, and varnishes applied after printing can also help reduce gloss differential. When using these types of non-native chemistry guard against staining and poor adherence, the tendency towards additive failure (reduction of gloss, dmax, or gamut), and possible reductions of longevity. (Download a free PDF review of PremierArt’s PrintShield sprays at www.johnpaulcaponigro.com.)

Bronzing 

Inkjet prints may display bronzing (an iridescent flash of colors seen at different viewing angles particularly noticeable in neutral areas). Heavier black plate generation and alternate screening frequencies (dot placement) dramatically reduce this. 

Longevity

Dye ink achieves significant lightfastness and ozone resistance only with a limited choice of swellable papers, which are not water-resistant and prone to running in high levels of humidity. (Epson’s new Claria ink is an exception whose longevity ratings approach 100 years on a wide variety of substrates.) Pigmented ink offers superior longevity and durability with lightfastness, water and humidity resistance, and ozone resistance on all media (swellable, porous, rag). Inkjet longevity ratings are reaching new highs in photography (for color108 years, 166 years with PremierArt Spray – for black-and-white 284 years and 312 years with PremierArt Spray). (See wilhelm-research.com for more information.) Longevity is derived from a complex set of factors chemistry, adherence, lightfastness, and exposure are a few of the key elements. Where longevity is a concern, use tested materials whenever possible.

Durability 

Durability can be seen as separate from longevity or an extension of it. Ink plays a role. Pigmented inks are prone to scuffing and burnishing. Sprays can reduce this tendency somewhat. Related issues such as scratching, cracking, flaking involve ink but are often more attributable to substrate. Handle with care.

Switching inksets

Choosing an inkset limits or determines your choice of printer model. While some printer models can accommodate more than one inkset (generally not simultaneously), printers are usually designed for a specific inkset.

Avoid switching inksets in the same printer, such as dye with pigmented or the printer manufacturer’s inkset with a third-party manufacturer’s inkset. Don’t confuse this with swapping inks within the same inkset, such as different ink cartridges of the same ink or different black inks designed for specific substrates, such as matte and glossy. Different inksets inevitably contaminate one another producing unreliable results and frequent clogging. If you do switch inksets, be sure to thoroughly flush a printer of all residual ink before installing a new ink type.

Epson K3 verus Canon Lucia

Third party inks

There are a number of third-party manufacturers who produce both dye-based and pigment-based inks – Lyson, MIS, Generations, ConeTech, etc. It’s nice to have a choice. Many users are happy with them. While these inksets often offer significant savings over the printer manufacturer’s inksets, I’ve never been as impressed with the quality they deliver. Third-party inks are prone to clogging. Longevity is often questionable. Using them sometimes voids the warranty on your printer. Buyer beware.

The bottom line

While it is only one factor you should consider when evaluating print quality, ink is of paramount importance. Choosing an inkset is one of the most important decisions you can make when selecting tools and materials to make fine prints with. Research your options thoroughly and explore all the related variables carefully before committing your images to print. Continue monitoring this rapidly evolving field. Its arc has been so stunning that in less than a decade, inkjet printing has changed the nature of the photographic print.

Read more on digital Printing here.

Learn more in my digital photography and digital printing workshops.

Color To Black & White Conversions – A Strategic Overview

Alignment XXIII

 

There are many ways to convert color images to black and white.
Here’s my preferred method.

1       Optimize Color

Start with an optimized color original; set black point, white point, and lightness; clear color casts; boost saturation to reasonably high levels; avoid clipping. Use Lightroom or Camera Raw.

2       Establish a Tonal Structure
Establish a tonal structure - the relative lightness and darkness of diverse image areas. For basic global conversions use Lightroom or Camera Raw. For advanced local conversions use dual adjustment layers – Hue/Saturation below Black & White.

(The primary goal of a black and white conversion is to set the overall structure of the tonal relationship in an image. During color to black and white conversions, you'll be tempted to perfect the lightness and contrast of an image. Resist this temptation, if it leads you to creating too much contrast, loss of shadow and highlight detail.)

3       Enhance Global Lightness and Contrast
Enhance global lightness and contrast, the relative relationships of tone, after you establish the tonal structure, the fundamental tonal relationships. Use Curves.


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Free PDF – The Aesthetics Of Photographic Prints

AestheticsOfPrintPDF
Half of the battle is knowing how to do something. The other half is knowing what to do. When it comes to making fine photographic prints, the road has been well mapped by our predecessors. One of the best ways to educate yourself about great print quality is to look at a number of great prints (directly rather than through reproduction). And, to keep on looking. Education, or enrichment, is a dynamic, evolving, lifelong process. Every time you look, sensitively with awareness, your vision grows. There’s always something more to learn.
A combination of elements (and their relationships to one another) is often evaluated when assessing print quality. Speaking very broadly, you could say, it’s all about believably reproducing detail. Focus, depth of field, high dynamic range, tonality, color balance, elimination of process artifacts all play a role. So do the selection of appropriate materials, scale, presentation and contextualization. There’s a lot more to it than you might think at first and though there are no hard and fast rules there are conventions everyone should be mindful of. There’s also a lot of room for creativity.
All of this is expanded and detailed in this free PDF – The Aesthetics Of Print.
Subscribe to Insights enews and download it free.
Learn more in my digital photography and digital printing workshops.

Why Make Prints ?

WhyMakePrints

This is an excerpt from my article on Digital Photo Pro.

Why Make Prints ?
Making prints does so many things for your images. How many things? Let me count the ways …
They’re …
Sensual
Prints enhance your images with material qualities and the associations they bring with them.
Sizeable
Prints define the scale of your images.
Durable
Historically, it’s the images that were printed that survived.
Salable
Because they’re physical, prints are easily bought and sold.
Exclusive
Images in print are more rare, as well as less accessible.
Presentable
Prints encourage images to be viewed in different ways.
What Making Prints Can Do For You
When you make a print, you consider your images more carefully for a longer period of time and often multiple times. This adds up. It’s quite likely that along the way you’ll find many ways to improve your images. Repeat this process many times, and you’ll find that your vision as a whole will improve.
Read more on Digital Photo Pro.
Learn more in my digital photography and digital printing workshops.

Masterworks In My Collection – Ansel Adams – Clearing Winter Storm, 1944

adams_clearingwinterstorm425

Ansel Adams’ Clearing Winter Storm, 1944 is a particularly interesting photograph to me because of its complexity. It’s a specific kind of complexity. Like many other complex images, it’s made of a lot of separate elements but is still unified. Unlike many other complex images, it can be broken into many separate images, each complete compositions in themselves; four peaks in clouds, one vertical monolith in clouds, shadowed valley between monolith and peak, waterfall and peak, waterfall and two trees, etc. (Try finding as many separate compositions in this single image like this as you can.)

When you look at prints of Ansel Adams’ Clearing Winter Storm many assumptions about the medium, the man, and his work are confirmed and challenged. It’s neutral, perhaps even slightly cold in tone, which is appropriate for the subject. The tonal scale is high contrast and full scale, perhaps heavier than expected with very full highlights and it may be surprising that some shadow detail is not preserved. The large format original renders detail well, though there are traces of visible grain in light smooth areas. There’s detail throughout the image (deep depth of field, sharp focus, full scale printing); when it was printed this may have been the sharpest image quality possible while today it looks classically smooth in comparison to new high resolution digitally sharpened images. At 16×20” it’s a medium scale enlargement, not a contact, and could have been printed larger; that it wasn’t is an interesting reflection on both the man and his times. Print quality becomes not only a window into the past of the subject but also into the medium, which this man above all others epitomized for his time.

(There’s a lot to be learned from looking at originals, which is why we look at masterworks from my collection in all of my  digital printing workshops.)

Find my comments on other Masterworks In My Collection here.
Learn more in my digital printing workshops.