Photoshop: Make color corrections before printing
Chromatic differences between an image on the screen and its printed version are common, though usually small. Here’s how to reduce them in Photoshop.
To reproduce the bright red of neon lights on a print is a real headache: you quickly fall out of gamut. It’s impossible to print such a red. What remains is to find a compromise that doesn’t sacrifice the atmosphere of the image.
One image, two versions
If you want to compare two different treatments of the same image in Photoshop, we recommend that you place the original and a copy side by side.
Simulate print
This comparison is very useful for visualizing a print on screen. This visualization, known as “soft proofing”, requires the use of a print profile, often called an ICC profile because of its .icc file extension (for International Color Consortium). A set of profiles is automatically integrated into the computer’s operating system when the printer driver is installed. These profiles are for the machine’s brand of paper. If you download an ICC profile from a third-party paper manufacturer (Canson-Infinity, Hahnemühle, etc.) or from an online lab such as Pictoonline, you must install it in the Windows\system32\spool\drivers\color folder for a PC or User/Library/ColorSync/Profiles for a Mac.
Why the image looks different
Similarly, the “Simulate Paper Color” option automatically selects black ink simulation. This operation darkens the image: the white of the paper is always less white than that of the screen. A slight gray haze appears: the black of the ink is shallower than that of the screen. If the image contains non-printable colors, they are translated by the closest colors available in the printing space, at the expense of less tonal differentiation and saturation. Perceptual rendering mode preserves some differentiation while slightly altering the color appearance. Relative mode is only relevant in the absence of non-printable colors. Black point compensation must be checked for relative mode to maintain good dark tone differentiation. It is optional in Perceptual mode.
Gamut
Depending on the printer and the paper, the color space, also known as the gamut, will vary. With the same printer, matte paper will have a smaller gamut than glossy paper. This increases the risk of unprintable colors. A profile indicates whether the printer/paper combination can utilize all the colors in an image. If there are no warnings about unprintable colors, everything is fine. Problems start as soon as they appear. From then on, color correction in Photoshop is essential.
Adjustment layers
Discover the photography courses at Spéos
Spéos offers various training courses ranging from simple one-week photography courses (initiation and advanced level) to 3-year courses. The long courses to become professional photographers allow you not only to master all the photographic techniques and its vocabulary (blurs, hyperfocus, sharpness zone, depth of field, backlighting, focal length, shutter release, autofocus, wide-angle, rule of thirds, etc.), but also all the stages of shooting and image processing.
Visiting the school allows you to discover the premises, the studios and the equipment, and is undoubtedly the best way to familiarize yourself with your future way of working. This is why, in addition to the open days, Spéos offers throughout the year personalized visits by appointment to come and discover the school with a member of the team.
Text and photos: Philippe Bachelier, teacher of Printing techniques at Spéos
