5.6. Hands-On Printer Profiling
Although some printers do not require calibration and some manufacturers supply excellent profiles for their printers, many printers do require calibration and need for you to create your own profiles to achieve the best results. These things are especially important if you use nonstandard media. There are many different color printers on the market, but the kind that almost all photographers use, because of both cost and quality, is the color ink-jet printer. For this reason, the printer that we are going to use for the examples in this section is the Epson 4800 ink-jet printer.
The Epson printer that we're using contains eight inks. Like many other ink-jet printers from other companies, it uses the standard four color inkscyan, magneta, yellow, and black (CMYK)that you need to make a color print. However, a few years back, the manufacturers realized that they could improve the quality of the printers by adding additional inks. They started by adding light inkslight cyan and light magenta. Adding these light inks improved the image quality, especially for photographic images, by reducing the graininess and improving the transitions of tones from dark to light. Then, light black and light yellow were added by some manufacturers for the same reason. Epson did not add light yellow, but in the 4800, they added a third very light black to improve black and white printing and also to reduce the amount of bronzing.
The first step in calibrating and profiling the Epson 4800 printer is to realize that its standard printer driver does not have a method for calibrating, as was mentioned earlier. If you want to calibrate this printer see "Raster Image Processors (RIPs)," earlier in this chapter.
Before we send our first print to the printer, we need to discuss the paper. Every printer manufacturer sells its own brand of paper that has been optimized to work best with its inks. However, a large number of third-party papers are available for these printers. Some of these papers are excellent, while others can be quite poor. There are numerous reasons for selecting these third-party papers, including cost, paper weight, surface, and so on. Keep in mind that, if you use any of these third-party papers, the color may not reproduce correctly and may require you to either create your own custom profile (as discussed next) or obtain one from the paper supplier, if available.
With that all said, we can now load the paper into the printer. To create a custom printer profile for our paper, we will need a software application that will create a printer profile and a device to measure this target. For this example, we are going to use an Eye-One Spectrophotometer and ProfileMaker software, both from GretagMacbeth. Each measuring device needs its own target, so let's navigate to the proper folder, ProfileMaker Pro 5.0.0/Testcharts/Printer/Eyeone. Because we are using the standard Epson printer driver, we will need to pick an RGB target. But isn't the printer a CMYK device? Yes, the printer is a CMYK device, but the Epson printer driver converts the RGB file to CMYK. If you send a CMYK test target, you will be unable to create a proper profile (unless you use a RIP that allows you to send CMYK targets; see the previous section on RIPs for CMYK profiles). For the target, we'll pick one of the TC9.18 RGB targets, which has 918 color patches. There are other RGB targets with fewer patches, but they do not yield as high a quality profile. After all, aren't you trying to create the highest-quality image? The 918 targets come in several flavors, formatted for different page sizes depending on your printer. Because we are working with an Epson 4800 printer with 16-inch roll paper, we'll pick the one labeled TC9.18 RGB i1.tif to save paper and ink.
We'll print this target from Photoshop. It's important that the Color Settings in Photoshop are set properly. When you open this image, you should see a dialog pop-up telling you that this image does not have an embedded profile. We'll open it up "as is," because we don't want to change the values of this target. Next, go to "Print with Preview" to turn off any automatic settings or color management, which would skew our results. It is also extremely important that we print the file out at 100 percent. If we change the size, we'll most likely receive error messages when we try to read this target later on in the profiling software.
There are a few more settings that you should be aware of in the printer driver. In the print dialog box, the third button from the top gives you many different options, but we are only concerned with two, Print Settings and Printer Color Management. The options in Print Settings that you will use are Media Type, Color, and Mode/Print Quality:
The second option in the printer driver that you need to know about is Printer Color Management. There are three options here, and you will want to select Off (No Color Adjustment).
You should realize that every time you change any of the these settings in the print driver, you are affecting the color, so you should make sure to use these exact same settings for each media that you create a profile for. Also note that you will need to create separate profiles for different resolutions. To spare you the trouble of going through all the options in the printer driver each time you print, you can save these settings in a preset. When saving the preset, be sure to use a naming convention that is descriptive and includes information such as the printer, paper, and resolution. A good name in this case would be 4800PremLust1440. Keep the name short so that you can see the entire name in the Presets window.
After the printer has printed the target, make sure that there are not any problems, such as marks, lines, or any other physical anomalies. Because inks take a while to stabilize, it's best to let the inks thoroughly dry before you measure the patches. For an Epson printer that uses pigmented inks, you should allow the paper to dry for 15 minutes. (As we noted in Chapter 4, if you are printing to a dye-based printer, it may take up to 24 hours for the patches to stabilize.)
Now you are ready to launch the ProfileMaker software so that you can create the profile. Because you are creating a printer profile, select Printer and then the target data TC9.18 RGB i1.txt for the corresponding target that you just output. Be sure that you have plugged the Eye-One into your computer. Next, select the Eye-One Pro as the measuring device for reading the target in the Measurement Data window.
ProfileMaker will then ask you to calibrate your instrument. This will lead you into the measurement window, where you can read the patches into the software. The Eye-One device allows you to read an entire strip (row) in at a time, which is much faster than reading the patches in one at a time. Take your time reading the patches. If you scan too fast, too slow, or too erratically, you'll receive an error message and have to reread the strip. With a little practice, you'll get the feel of the instrument, so don't get discouraged in the beginning if you have a few errors. The software will prompt you as to which line to read.
After you have read in all the patches, which should take about 15 minutes, the software will inform you that you have successfully read your patches. When you close the window, you'll be prompted to save the data. Save your file in the Measurements files folder, which is found in the ProfileMaker folder. Again, be sure to use a descriptive name.
This data that you just saved will now appear in the Measurement Data window. If it doesn't, navigate to the folder where you saved the data and load the file. The software has numerous options for creating a profile. Based on my experience, I suggest you use the settings that appear by default as a starting point. Feel free to experiment and find what works best for you.
Two settings that you should be aware of are "Viewing Light Source" and "Correct for Optical Brightener." The Viewing Light Source is relatively unique to this particular application; it allows you to change the overall color of the profile to compensate for the viewing conditions. Use D50 as your default because it is a lighting standard in the United States. If you are viewing under other lighting conditions, pick the one that is closest to what you are using. "Correct for Optical Brightener" will become available if the paper that you are using has a UV optical brightener to make the paper appear whiter. As discussed in Chapter 4, in order to make a paper appear whiter, the UV brightener is actually made more blue and therefore needs to be compensated for when creating the profile. Some spectrophotometers have a UV filter on them to prevent this from being a problem. However, if you encounter a paper with a UV brightener and your measuring device does not have a UV filter, this checkbox will be available and you should select it.
You are now finally ready to create your profile. Give it the same name as your measurement data so that you don't become confused. The next step is to use this profile to produce a great print.