AzPicLady wrote:
I have some HP paper left over from my old printer. I do print on it with my Canon printers, but it turns out overly magenta in tone. I do have to set things specially for it if I want it for anything other than checking density and balance.
A custom ICC profile would correct the magenta hue, without any special adjustments needed.
Many folks here do not understand color management. The following is directed at new users:
ICC color management is the process of making very different devices display reasonable simulations of the same colors.
Color management is performed by your operating system or software. The OS automatically converts the color values of a file to a standard "working color space" that it can use to match colors from device to device to device. For instance, a JPEG in
sRGB color space is converted to the
working color space, then to the
monitor profile color space for viewing, then
also to the
printer/paper profile for printing.
***If the monitor profile is wrong, probably because the monitor is not calibrated and custom profiled, your prints will not match the monitor!
***If the printer/paper profile does not match the printer, paper, and ink combination used, probably because you don't have the right profile, or you set something incorrectly, your prints will not match the monitor!
Profiles rely on
device calibration. For instance, before profiling, you calibrate a monitor (with the aid of a hardware device known as a colorimeter or spectrophotometer) to linearize the three color channel response curves for red, green, and blue output. In simpler words, at any brightness level from black to white, a calibrated monitor produces a perfect neutral gray by combining red, green, and blue light.
Once the monitor has been calibrated, profiling software measures its output with the same colorimeter, and creates a set of lookup tables that adjust the INPUT signal to the monitor to make correctly color balanced images look as close to normal as possible. "Normal" is an international standard set by the International Color Consortium, or ICC. If you work on a calibrated monitor, you can trust that prints made on a calibrated and profiled printer/paper combination will appear very, very similar. This is a remarkable feat, considering that the monitor makes white light and all other colors from red, green, and blue phosphors, and an inkjet printer makes black and all other colors from *at least* cyan, magenta, yellow, and black ink (CMYK — the K is Kontrast). Some printers mix as many as a dozen different colors for finer color subtlety.
Calibration of a PRINTER works much the same way as monitor calibration. Depending upon the printer type, it may or may not require calibration before profiling. All "wet process" mini-labs and similar devices must be calibrated frequently to maintain consistent color balance. Process monitoring greatly affects this calibration, so the printer and process are considered as a system. Profiles generated when the device is "in perfect control" are therefore most useful.
With printers, once the operator knows the printer and process are linearized for a given paper, (s)he prints a set of test charts or strips that contain up to 500 or more colors. Then, a colorimeter or spectrophotometer is used to read each color patch (manually or automatically, depending upon the sophistication of the calibration and profiling kit).
With inkjet printers, there is no calibration step. They are calibrated at the factory, and any minor deviations are handled via a custom profile. You need a SEPARATE profile for each exact combination of printer model, ink set, and paper. Profile mismatches create color casts and other weird looks.
Printer manufacturers build paper profiles for their own paper types. When you install the printer driver, the manufacturer's profiles are installed as well. When you choose an OEM paper by name in the driver, the driver uses the correct profile, so long as you choose "printer manages color" in your software.
However, if you use a third-party paper, you need a profile for that paper! You can download profiles for most popular printer/ink/paper combinations directly from the paper vendor's web site. OR, you can make custom profiles for your specific sample of a given printer, with a particular off-brand ink set, and a particular paper. When you print, you select the profile in your software and choose something like, "Let Adobe Photoshop manage color."
It's pretty safe to assume that Canon, Epson, and HP do not make profiles for each others' printers to use the others' papers. In such a case, you would need a custom ICC profile.
Hopefully, this provides some insight into why your prints don't match your monitor. ESPECIALLY if you record and adjust raw files, rather than saving JPEGs at the camera,
you need to work on a correctly calibrated and custom profiled monitor.