The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that the prior art forms part of the common general knowledge.
The Print Preview is a common technique for proofing a document before creating a physical printout. The Print Preview can be used to find errors that would have occurred in the physical printed document. By fixing such errors before creating the printout, it is possible to save money, time and resources by reducing or avoiding the need for physical proofs.
Many printers use a set of primary colours, typically Cyan, Magenta, Yellow and Black, (CMYK printing) which are combined on the page in various quantities to produce a range of colours, the full range of which is called the printer's gamut.
A problem occurs, however, when computer displays are not capable of displaying all the colours and properties that physical printers can produce. Even a calibrated display may not be able to accurately represent the full gamut available to a physical printout.
To overcome this problem, an existing solution is to choose colours for the display that are as similar as possible to the printed colours. In many cases, this is sufficient. In other cases, modern displays have a sufficiently wide gamut that the printer's gamut is fully displayable, providing such displays are colour calibrated.
This problem is exacerbated when special colours, called characteristic or spot colours, are added to a printer to (amongst other things) further improve the printer's gamut, or simply to print particular colours accurately or at low cost, for example, frequently printed company logos. Such spot colours are typically difficult to render using a normal display.
If a calibrated display can accurately represent such a substance using a flat colour, doing so may conceal where that substance is to be printed, since it appears similar to any other normal process colour. This can be overcome, for example by outlining the spot colour location, to indicate where the spot colour will be printed.
However, this problem is exacerbated when a spot colour substance has unusual properties, such as when the appearance is dependent on the physical surroundings where the printed material is viewed. This can occur if the colour depends on viewing angle, the colour fluoresces under ultraviolet light, varies with temperature, or is reflective. For example, a golden metallic substance may both reflect some of the colours and shapes of surrounding objects or lights, while simultaneously imparting a yellowish tint to that reflection.
In this situation, even highlighting or outlining the region, or even replacing the spot colour with an alternative flat colour does not mimic the colour properties, and hence the appearance of the physical printout. Consequently, current techniques do not allow accurate preview of the printing of such documents and it therefore remains impossible to make fully informed decisions about the nature of the physical printout, without actually printing it.