As far as we’ve come in inkjet and laser printer technology, there is still one major drawback from a proofing perspective: Printers as a rule print with four colors to make up a “full-color” piece – namely cyan, magenta, yellow and black. There are some spot colors which simply cannot be recreated accurately with these colors, let alone combinations and shades of spot colors. Depending on the colors used in the design, you may see a small or large variance from the computer screen to the inkjet proof to the final printed piece.
There is often a small leap of faith in this process. The only way to get an accurate sense of the final piece is to request a press check of the job when it is first put on press.