The Gray Component

The Gray Component

In a CMYK separation Cyan, Magenta and Yellow are often combined to create the Gray values and tones in an image.  When using Gray Component Replacement (GCR), in a CMYK separation, The amount of Black that prints into these areas can be adjusted by changing the GCR amount.

When separating an image using the YRGBK script, all of the Gray values and tones are handled by the Black, Gray or Gray Component channels. The color channels only contain Hue and Saturation information for the image, and are not blended to create gray or tones.

• Gray values and tones that would be printed using CMY, in a CMYK color separation, are put on the Gray Component Channel by checking the Gray Component check box.

The Gray Component Ramp

When the Gray Component check box is selected, a second dialog will be presented with the Gray Component Ramp setting. This slider determines the amount of black that is moved to the Gray component channel. Values added to the Gray component are removed from the Black channel.

• A higher setting increases the amount of Gray Component, and decreases the amount of Black.

A Light Black

The Gray Component channel in YRGBK 2.3 can be treated like  a light black channel, and can be printed using an extended, or transparent Black ink. Splitting the black in this manner offers several advantages. This includes the ability to use a transparent ink, a harder squeegee, and a lighter touch on the light black channel, while allowing for good saturation and contrast provided by an opaque ink and a heavier impression with the regular Black.

• Splitting the blacks provides some flexibility in the printing of an image, although it does add an extra screen to the process. Unchecking the Gray and Gray component check boxes puts all the value information on the Black channel.

The Gray Channel
The Gray ramp is displayed when the Gray check box is selected,

Gray values are  removed from both the Black and the Gray Component when the Gray check box is selected. The Gray Slider determines how far the Gray prints into the colors, with higher values increasing the amount of Gray printing into the colors themselves.

The Gray Ramp

With the Gray check box selected, a second dialog containing the Gray Ramp slider will be presented. The Gray Ramp slider determines the value of the gray, with higher numbers generating a darker gray, and removing pixels from both the Black and the Gray component.

• The Gray slider Combined with the Gray Ramp settings determine the balance between the Gray, Black and the Gray component. The Gray Slider determines the amount of gray in the colors, and the Gray Ramps determine the values.

The Gray Component channel provides a useful option for printing photo realistic images and any color separation which would benefit from greater control over the values in an image. The Black channel which is created by checking the Gray component option is the same  Black that would be created when generating a CMYK color separation. With the Gray and Gray component options Unchecked, this information is retained in the Black channel, providing the full range of values in a single channel.

The Gray component ramp settings increase the amount of Gray component. From Left to right, using minimum, default and maximum settings
Increasing the amount of Gray component reduces the amount of Black. The Black channels in this image correspond to the gray component channels above.