A digital proof is a colour and legally binding test print for the graphic arts industry. A digital proof simulates the colour of the subsequent offset printing or gravure printing within the narrow tolerances of ISO 12647-7. It enables designers, photographers and printers to check the appearance of a print product in terms of colour accuracy, image quality, text legibility and positioning of elements before it goes into mass production.
Today, it is almost exclusively calculated using a RIP and then produced with pigment inkjet printing machines on special proof papers; earlier processes such as chromalin etc. are no longer found on the market today.
The digital proof data is converted into separations and then reassembled into a composite image in order to correctly simulate overprinting and trapping. The data is then transferred as a newly generated composite to an inkjet printer, usually with more than 8 colours, which prints the data. In addition to the print data, a digital proof must also carry a UGRA/Fogra media wedge in order to be colour-accurate and legally binding. Thanks to the standardised wedge, the print shop is able to check the proof for correctness. As many print shops do not have this measurement technology to hand, the proof is often provided directly with a test report that shows the correctness of the measured values of the media wedge directly on the proof.
The term digital proof
In addition to the term ‘digital proof’, terms such as ‘colour proof’, ‘proof’ or ‘online proof’ are also commonly used.
ISO 12647 defines the term ‘validation print’ (ISO 12647-8) in addition to the highest standard of the contract proof, or ‘proof’ for short (ISO 12647-7). The validation print is characterised by the fact that it is less accurate in terms of colour, but can also be produced on laser printers. Compared to the contract proof, however, it accepts significantly higher colour deviations and is only legally binding after prior agreement. A real ‘proof’, i.e. a real contract proof according to ISO 12647-7, is currently not only by far the best variant in terms of colour, but also the only legally binding proof.
A digital proof can give a very good idea of what the final printed product will look like, but even the best proof cannot fully simulate the actual printing process and the materials used. Therefore, there may be slight deviations between the digital proof and the actual print result. The offset screen or even a moiré appearing in the final print cannot be reliably simulated in advance due to the lack of screening in the digital proof.
Further information:
https://en.wikipedia.org/wiki/Prepress_proofing
How to print dotproof printing in epson surecolor P-5000
can i know a free software
As far as I know, at present only GMG ColorProof offers a dot proof solution. But of course, this is no free software, but rather expensive.