Piezography K7 (K6) is a system of seven (or six) shaded monochromatic inks and matching media “profiles,” that when used correctly produce a perfect black & white ink density linearization on a specific media on a specified printer. Piezography K7 (K6) uses a special profile that I make that is compatible with the QuadTone RIP (QTR). However, it is not a traditional QTR profile that can be made with QTR. As such, it can not be edited nor can it be used as a base for making additional QTR profiles. A traditional QTR profile is a set of adjustment points for curves that can be manipulated in QTR. This is a process which the user of QTR can learn. However, a Piezography made curve is much smoother, has greater ability to print higher resolution, and is extremely linear from dMin to dMax. A Piezography made curve differentiates between 256 gray levels. It is the highest possible standard with which you can print your black & white prints.
A Piezography “profile” is actually a set of curves that correspond to what tonal information from an image is printed with a particular ink shade. With six and seven shades of ink, an image is divided in such a way that the tonal responsibility of the inks can be very complex. The QTR curve-generation tool can be mastered by most users who are attempting to control three or four shades of ink. But it is too difficult to produce a perfect linearization with six or more shades of ink. Therefore, Piezography created its own profiling application that can output a QTR “compatible” curve set. The combined curves are actually called a “curve” in QTR. Piezography K7 & K6 curves are compatible with the print driver of QTR, but not its curve making tools. Therefore, the Gamma and Ink Limit of a Piezography K7 or K6 curve can’t be adjusted in the QTR interface without adverse effects. But, they should not need to be adjusted in order for the user to have the best results.
A Piezography curve is the best possible system available for creating a perfect black & white print. Even though a professional RIP is available that supports Piezography K7 inks in large format printers, its profile making engine is not at the same standard as the Piezography Profiler which I use for making my Piezography QTR K7 & K6 curves. Also, Epson will nno longer permit support for Piezography inks in this professional RIP. The last printers supported are the 3800, 4800, 7800 & 9800. The new 4880, 7880 and 9880 printers are only supported in QTR.
In order to illustrate how a Piezography curve functions we can think of them in a more familiar format such as the Photoshop curve. A graphic representation of an idealized Piezography curve looks like this:
The idealized Piezography curve
An actual Piezography curve for QTR can be visualized in the QTR tool set. It looks like the following:
An actual Piezography curve previewed in QTR tools
Using Photoshop curves its possible to show you what each of the ink curves inside a Piezography curve actually do. Each one of the curves above is responsible for a single shade of ink. Yellow is the lightest shade 7. Light black is shade 6. Light magenta is shade 5. Magenta is shade 4. Light Cyan is shade 3. Cyan is shade 2. Black is shade 1 (black).
Now the example curves in Photoshop:
Shade 7 the lightest ink
Shade 6 ink
Shade 5 ink
Shade 4 ink
Shade 3 ink
Shade 2 ink
Shade 1 ink
Now unfortunately, Photoshop can not create a seven channel file using seven curves in order to print an image using seven monochromatic inks. But you do not have to worry about that! Piezography supports the QuadTone RIP which can take a single channel grayscale image file and using the Piezography K7 curves, divide the image perfectly into the seven inks so that the effect is a perfect linearization.
We provide a number of free Piezography curves for the most popular papers. A Piezography K7 or K6 curve:
Uses as many overlapping ink shades as possible in order to produce the best possible results on a wide range of a particular printer model, even if an individual’s printer is just slightly out of spec.
Uses the least amount of ink possible to create the best possible result.
Uses a long trailing edge structure in each curve to fill in the spaces between dots in darker inks.
Uses as little as possible dark ink in a lighter shade to make dots invisible with even a strong magnifier loupe.
Prints 255 distinct shades of gray from black to near paper white.
Reproduces a visual Gamma of 2.2 as print in order to replicate a Gamma 2.2 calibrated monitor.
The Piezography K7 and K6 curves should be suitable for most users unless:
A printer is too far out of spec and does not produce a good result with the “canned” K6 and K7 curves.
As a printer’s print heads begin aging the size of the drops produced is not always as accurate as intended.
A printer’s print head has become too old to produce micro-dots.
The user wishes to print on a paper I have not profiled.
The media manufacturers sometimes change their media coatings slightly which changes the expected results of a “profile”.
A user is in an unusually high or low elevation in comparison to East Topsham, Vermont (860 feet above sea level.)
A user wishes to have a glossy compatible Piezography MPS profile.
A user may wish to have a perfected system for their particular printer
Any of the above are reasons why you may wish to have us custom profile your printer. We have been profiling customers Piezography systems on a custom basis since 2002. We provide the customer with a target to print through a special Master Curve. The customer prints the target and returns it to us for measurement and profiling. There is a charge for this service. As of this writing we are now offering reduced rates for those users with a spectrophotometer for making their own measurements.