Hi Everybody,What's a "rich" black.My photos are posted on the web. They are also printed at COSTCO in various sizes from 4" x 6" to poster sizes. COSTCO uses a photographic printer for the smaller sizes and an ink jet printer for poster size prints.My final files are made in PhotoPaint and flattened in a TIF or JPEG format.Phil
Black at 100%K tends to be on the gray side as it's just one color. Rich black uses CMYK to create a darker black. A rich black. ie 100%K 100% CMY
I'm not sure exactly where you are going with the question. What are you trying to accomplish?
"Rich Black" means a black composed by more than one ink. The CMYK Black is a "transparent" o translucent ink (the Pantone Black is opaque), then if you use a background or a big mass of black, the result is not so dark as we want. Moreover, if the printer increase the drkness (ie, adding more pressure to the Black), the images will become darker, and all shades of black will be increased proportionally also.
Usually, most printers use 40% Cyan + 100% black for a darker black. Sometimes, it's used 40% cyan, 40% Magenta, 40% Yellow and 100% Black (it's more complex use the 4 inks for some printers), and sometimes, it's used two black plates, one for the shadows of the images and other for the background. So, there're several workaround for solve the problem.
"Pure Black" it's the opposite of "Rich Black". If you have a grayscale image, you will have a pure black only. The most evident difference is the price: one ink instead four. But also is about quality. While you can create a wide range of shades using RGB/CMYK (ie more yewllowish, more blue, more dark, more light, etc) if you use only black (grayscale) you can have a better image quality since it's only one ink and preserve better the shades and tones of the image, specially the lighter tones.
one more think: althoug for image retouch is better to use RGB (you have more shades of each color), remember that if the image will send to print, it will be converted to CMYK. Then, the colors will change. The RGB Black (0.0.0) is a really dark black, but this is not the same color when send to print. First, printers don't want to use 400% ink coverage (100% of each ink) because it's very difficult and cause several mistakes. According with the Colro Profile, each kind of paper requires a different Total Ink Coverage. It could be 300% max, 320% / 340%, etc. Those values are included on the color profile. And although you don't want to use it, and although you don't include any color profile (a big mistake but a common mistake) the file will send to print using any color profile. If you don't include any color profile, when the file is sent to CTP for print, it will include a color profile and values will change if are not correct (for example, if you use a 400% ink coverage (100% of each) surely it will be replaced automatically on almost all prepress services (usually, it's a default setting)
Like this?
Or this?
Apologies, files size limited on this site, so the quality is a little off.