Proofing for print
Proofing is a crucial stage in the printing production cycle. It is important that you understand how this process works, what your options are and what are the implications of signing off a proof ready for print production.
Whilst every effort is made to ensure that the document is prepared correctly, ultimate responsibility for ensuring that the document is correct lies with the client. The proofing process is the stage that these checks are implemented. You need to satisfy yourself that the proofing method you have chosen is suitable for your needs, and that the proof supplied has been thoroughly checked before agreeing for the job to be sent to production.
A Commercial Printer’s job is to ensure that the job they produce is accurate to the proof you have signed off.
Various proofing methods:
There are several methods of proofing a document prior to production, depending on your proofing requirements.
Screen PDF (Softproof):
A Screen PDF gives a proof that confirms the layout of the document to be printed. The layout, typography and positioning of elements in the final printed piece will be accurate to the Screen PDF supplied. This is the most popular proofing method used by our clients and is provided free of charge bu greenhouse.
A Screen PDF should not be considered to be colour accurate, due to the calibration settings of various computers and monitors it is viewed upon. Also, it is very difficult to tell how pixel based images and pictures on a Screen PDF will print when reproduced in a commercial printing environment. This reflects the need for higher resolution images to be used in the lithographic printing process, than is required by a PC monitor.
If you print out the pdf supplied to your desktop printer at your premises, you should not assume that the colours you reproduce will be the same as those supplied to you in the final printed piece. Colours produced locally are nearly always innaccurate unless the desktop printer has been calibrated to professional settings. Even if your desktop printer has been calibrated, the Commercial Printer will not agree to match any colour from your desktop printer. Only Contract Digital Proofs supplied by ourselves should be considered to be strongly colour accurate.
Use a Softproof PDF to check page layout, spellings, and design features only.
Non Contract Digital Proof:
A Non Contract Digital Proof is a hard copy printed proof supplied to a customer. The Non Contract Digital Proof has all the same benefits of a Screen PDF (Softproof), but is supplied as a hard copy. It is often easier to spot typographical and layout errors on a printed piece rather than on screen.
In terms of colour, the Non Contract Digital Proof should not be considered colour accurate, but is normally much closer to the actual colours in the final printed piece (dependant on the paper used) than a Screen PDF softproof.
Contract Digital Proof:
A Contract Digital Proof is a calibrated hard copy printed proof supplied to a customer. The Contract Digital Proof has all the same benefits of a Screen PDF softproof, but is supplied as a colour calibrated hard copy.
The Contract Digital Proof is produced on a calibrated inkjet printer and can be considered 90% accurate in terms of colour to a job produced on a lithographic printing press using a coated sheet in CMYK. This type of proof combines all the benefits of Non Contract Digital Proof, but provides a strongly indicative representation of colour, when printing the final piece on a coated sheet in CMYK.
The Contract Digital Proof cannot be 100% accurate because of the differences in screening technologies used by the inkjet proofing system, and the different paper stocks used in the final printed piece.
In terms of colour, the Contract Digital Proof should not be considered colour accurate if you are not printing the final piece on a coated sheet. If you are printing on an uncoated sheet it is very likely colours will not be accurate. In addition, if you are printing the final piece outside of the CMYK colour model (ie additional spot colours and metalics) or with additional effects (varnishes and laminates), these will impact on the colour produced on the final printed piece which cannot be replicated by the Contract Digital Proof.
Press proofs are the ultimate proof, because they use the same material, process and paper as the final printed piece. They will be a very accurate representation of what the final printed piece will look like.
A press proof will not show the effect of additional post press processes on the printed piece such as a lamination, foiling, Spot UV or Overall UV Varnish.