Piezography K7 is the latest generation of product and is a sharp contrast in quality and longevity when compared to EPSON K3 printers and their Advanced Black option. While EPSON has just recently introduced printers with seven and eight inks, they have only introduced three black shades of ink. Piezography which first introduced 4 shades of black ink in 2000, introduces seven shades of black for these printers. Piezography takes advantage of the seven inkjet heads in EPSON printers to produce significantly higher quality monochromatic prints, than can EPSON with only three shades of black ink.
But, Piezography is more than just changing out the color inks in your EPSON printer and replacing it with Piezography shades of carbon black ink. You also need a special software to make the effect work. Piezography is inks and software working in harmony. Jon Cone develops a profiling application with which he produces K6 and K7 profiles for Roy Harrington’s QuadTone RIP. This combination is to date the highest quality implementation of the Piezography system – yet it is amazingly affordable. QuadTone RIP is only $50 and includes the Piezography profiles at no additional charge. For large format printers QTR can be used to amazingly good results for such an inexpensive RIP. StudioPrint by ErgoSoft includes a Piezography ink profiler in their product and we have long enjoyed their support for our inks. The advantage of a StudioPrint system is the ability to customize the inks – a subject entirely unto itself.
Because Piezography uses seven shades of black ink with which to produce the highest quality monochromatic photograph, Piezography can reproduce the image in a much higher quality by moving the printer dots of ink significantly closer together than can EPSON. Epson needs to dither its three shades so as to fool the eye into seeing more gradations than there are. K7 curves do not use any of the low frequency dithering patters (that include dots of ink far enough apart to allow paper to be visible between them). Piezography K7 curves only print at the upper frequencies where image detail is not lost to invisible paper white (the space between Epson dithered dots) but is rather presented in the final print has enhanced detail.
Resolution of over 360dpi is wasted on the Epson printer when used with conventional Epson driver or RIPs. However, when Piezography K7 curves are used with the QTR RIP – a resolution of up to 2000dpi results in extreme levels of detail. However, using increased resolution is defeated by resizing images in Photoshop. Photographers will want to capture as much resolution as possible in the original image via capture or scanning. We call this true optical resolution.
Piezography provides a set of ink curve sets for the QuadTone RIP driver that directs the EPSON printer to print each shade of Piezography black at a significantly higher dithering frequency. The best way to represent this is to put the two systems to a test which illustrates this concept and reveals the strengths and weaknesses between the two systems.
And below is an illustration of the curves architecture of the Piezography K7 Master Curve.
From left to right represents the output gray ramp. Above each part of this ramp are the inks that are responsible for printing that particular density of tone. The higher the curve, the more density of ink that is printing and therefore the closer the dots of ink are printing. The deep blacks are made with Shades 1,2,3&4 and an area such as 85% gray is comprised of also of portions of those 4 shades. The mid-tone gray on the other hand is comprised of portions of Shades 4,5,6&7. The highlights and 1/4 tones are where our eyes perceive detail. In the instance of Shade 7 it is printing very high up on the curve at nearly maximum density. By contrast, the Epson light black shade would only be printing at a low density because it requires a wider spaced dither to give the illusion of being very very light. Piezography actually prints a very, very, very light black shade of ink. It has the luxury therefore to print at higher frequencies eliminating the space between dither dots and producing tons more detail!
Finally – here is an actual density comparison to the three shades of Epson black inks in comparison to the seven shades of Piezography K7 inks:
Perhaps this illustration is easier to visualize how having additional shades of gray allow an image to be divided into more mathematical gray variations. The Piezography K7 curves actually contain the ink density recipes for more than 64,000 gray levels.