Inkjet Paper Tests (NOTE: NEW PAPERS ADDED - JAN 14, 2011)

All papers that I use are thoroughly tested before I use them for printmaking. The papers must be capable of the best quality I can achieve. Other people have spectral analysis results available on the web. That’s important, but the most important test that I conduct with my Epson 3800 printer is an ink (pigment ink in this case) reception test by a comparative method. It’s a real torture test, and it quickly reduces the final paper selection to a few excellent papers of any given type. If you have a spectrometer, such as an X-rite i1, you can easily do the same test.

This test method makes use of Roy Harrington’s excellent Quad Tone RIP (raster image processor) calibration printout. The printout is primarily intended to enable linearization of black-and-white output. In other words, making the tones from white to black plot out as a more or less straight line on a graph. It could also be used to help linearize color, as it does print from each of the printer’s cartridges, but the black and gray cartridges are sufficient for my paper inking tests. Color would only add unnecessary complexity. Even if you don’t have a spectrometer, you will see many of the differences between papers with an objective means of comparison.

How it works:

What the Quad Tone RIP calibration printout does is to simply push ink from each cartridge in 5% increments from 5% to 100% ink. So, from each cartridge, there are 20 patches printed out in a row. For the Epson 3800, there are three important channels for this test; black (either PK for glossy papers, or MK for matte papers), light black, and light-light black.

Once a printout has been allowed to dry for a minimum of 24 hours, I read each row of the three black and gray cartridges at least three times with a non-UV filtered device that reads reflection density. I average the three sets of readings and plot them as three curves on a density graph using an Excel spreadsheet. One can also visually compare the printouts while studying the measured data. Many of the effects that show up in the numbers and the graphs can be seen on the printouts.

The printout makes no use of profiles or driver rendering selections other than dots-per-inch (dpi) and paper type. It uses the appropriate black cartridge for the paper type selected, but otherwise makes no adjustments. Most of my test charts have been printed at the maximum setting of 2880 dpi (2880 x 1440) but at least one shows improvement at 1440 dpi (1440 x 720), and others show the pitfalls of using the wrong paper type setting.

To view the charts, select “Paper Test Charts” in the menu above. Here’s what you will see:

An example of the Quad Tone RIP calibration printout is shown as the first item in the display of charts.

You will notice, when you move from one chart to the next that they are all graphed at the same size and scale for easy comparison. You may also need to use your browser’s scroll bar to read the lower data on a small monitor, but the graphs tell much of the story.

The top curve shows the densities from the “K”, or black cartridge as read on the top row of the printout. The second curve shows the densities from the “LK”, or light black cartridge, second from the bottom row of the printout. The bottom curve shows the densities from the “LLK”, or light-light black cartridge from the bottom row of the printout.

Each of the curves shows the response of the paper as the ink gradually loads up with ink. Some papers produce nice smooth curves that would make profiling or linearizing their combined responses easy. Others show odd bumps in the curves (confirmed to be real and often visible) and even unexpected reversal as they approach maximum black ink. Apparently the ink gets “shinier” and even visibly loses light absorption. This won’t make my work easier or the resulting prints better, even if the paper has an impressive Dmax (maximum density) somewhere before the end of the curve. Some papers reach their Dmax about midway through the curve and then flatten out, again an undesirable trait. Most glossy inkjet papers achieve a higher Dmax than traditional silver prints. One example shows that reducing the dpi setting from 2880 to 1440 produces a smoother curve at the end. An attempt to use glossy paper type for a particular matte paper (as suggested in a forum) did not produce the claimed improved results. Even if a curve has a reversal before the maximum is reached, it can be profiled, but some ink limiting will be required to stop the ink buildup before the reversal occurs.

Black minus White (b-w) Numbers:

I’ve included the difference between paper white and Dmax as “b-w” in the data. This number is very important as the perception of black and white can be relative. One can affect the perception of the other.

Other Indications:

Other traits observed on the test prints include whether the paper appears to make use of optical brightening agents (OBA’s). This is most often indicated by a negative “b” number in the Lab readout of the paper white, though it takes a spectral analysis to tell for sure. Apparently, with some inkjet papers, there is some merit to the argument that the OBA’s can fade even in dark storage due to chemical reactions. Recently, I’ve observed that some matte Hahnemuhle brand papers lose their brightening agents very quickly when stored adjacent to certain “archival” clear materials containing plasticizers. Paper white rapidly becomes a noticibly different color than the same paper from an unopened new box. I’m sure that many other inkjet papers behave the same way. Further testing is required, but it appears that many papers react badly to solvents, such as those found on many adhesive tapes.

With the paper test printouts, I can also easily see whether bronzing is present, and it’s comparitive severity. These factors, as well as the paper surface quality, sharpness, handling characteristics, and image stability and longevity, as tested by others such as Wilhelm Imaging Research, play important roles in my paper selections.

Following are charts of some well-known matte and “glossy” papers as tested with my Epson 3800. (The newer Epson 3880 may have slightly different results, but probably not enough different to invalidate the findings) More results will be added as new papers come out, or as papers change. If you would like to know more, or have a favorite paper that has not been tested here, please feel free to contact me.