Sometimes advertisers observe that their printed vinyl colors don’t look like they do on their computer screen when checking their proofs. Some other times, they don’t even look the same between their office, their home or on their iPhones. It’s a bit of a complicated topic, but basically it can be boiled down to the printing environment and the digital world.
Computer monitors and LEDs emit color as red, green and blue light (RGB). Although all colors of the visible spectrum can be produced by merging red, green and blue light, monitors are capable of displaying only a limited range of the visible spectrum due to the manufacturing processes. Your scanners, iPhones and cameras capture your pictures in RGB and save them most of the times currently as JPG files for use over the internet. Interestingly, if you hold the same picture on your iPhone next to the same displayed picture on your monitor, the colors will most likely not be the same either. Even the same monitors on different computers will appear differently. Those serious about the differences must calibrate the monitors against some given parameters, but it’s not needed by most folks at all.
While monitors emit light, inked paper/vinyl absorbs or reflects specific light wavelengths. Cyan, magenta, yellow and black pigments (CMYK) serve as filters, subtracting varying degrees of red, green and blue from white light to produce a selective array of colors visible to the eye. When you print a picture from your computer, it will be in CYMK (as your color cartridges show) and the software in the computer roughly coverts the file information of RGB to CMYK format to be printed. Test it out and hold the printout next to the monitor and see what a difference there is.
Those of us in the advertising world must use both types of files which have little interest to the advertisers. We very well know, it’s just gotta look great! Generally speaking, RGB format allows us to use more brilliant, neonish colors which work great on the digitals, while the CMYK format allows us to communicate correctly with the folks printing the vinyls for the billboards, but generally have a more subdued, or dullish portrayal of the colors. The trick is getting them to work well for both venues, then communicating with both the advertisers and printers for approvals.
Here are a couple of examples to show you roughly what the differences are in the real world, done so you can view it on your computer screens.