What is 4 Color Process?
D-Lux has the capabilities to run up to 100 dpi (dots per inch) on four color process printing. 4 Color Process is the best way to achieve a wide color gamut by printing only 4 colors, cyan (blue), magenta (red), yellow and black.
What is Line Count?
What line count does is give the viewer the impression there are no dots when visualized at a certain distance. The rule is 240 divided by the dots per inch. This is where the human eye no longer sees the dots but sees a complete image.
240/100dpi = 2.4 feet --- Used for continuous tone at arm length
240/85dpi = 2.8 feet ----- Counter displays
240/65dpi = 3.7 feet ----- Overheads behind counters
240/55dpi = 4.4 feet ----- Displays
240/25dpi = 9.6 feet ----- Signage
When the dots are printed on top of each other another color is achieved. Example Cyan on Yellow is Green, Magenta and Yellow is Orange, etc.
Four Color Process is a precise printing process. Each of the 4 colors needs to be printed within a tight tolerance otherwise there will be a color shift.
In order to achieve an acceptable finished 4 color print, it is necessary that we have a great piece of artwork. Ideally any hi-res computer file would work. Low-res files are not recommended as the finished print may not be visually acceptable. Any PC or Mac program will work with Photoshop being the most commonly used. JPEG or GIF are also acceptable. Any fonts or linked imaged in the file should be included when sending artwork.
If there is no computer generated artwork file then a sample or original photo/transparency would be required. If a printed sample is all that is available it can be used but the final print quality will be drastically reduced.
Halftones / Dot Gradients
Similar approach but printing spot colors to achieve a fade, either one or two colors to give the effect of light to dark.
Again the above chart for line count (dpi) holds for the distance that the dots disappear. This is less noticeable if the color doesn’t contrast to the color below for any given distance.