What do you mean – not all pdfs are the same?
Adobe’s PDF (Portable Document Format) was invented so that formatted document files could be viewed over different computer systems without needing the same software. For example, a designer working on Mac in Quark XPress can make a pdf of a document which can be viewed and printed out by a client using a PC and Word. Additionally, the pdf process drastically reduces the size of files which makes them much more – well – portable! The piece of software which allows people to view the documents – Acrobat Reader – is free, and is bundled in with nearly all computers or can be downloaded from Adobe.
Making pdfs through Word or Acrobat & Distiller
PDFs can be made directly from Word and various other programmes, but the specifications for the resulting files are not as customisable as using Adobe’s professional Acrobat Distiller programme. Making pdfs through Distiller is more time consuming but offers the option to change resolution, font embedding and other essential settings. Adobe Acrobat (which includes Distiller) is a paid-for programme, and is not the same as the free Acrobat Reader which opens pdfs for viewing but doesn’t create them.
We use Distiller to make pdfs for either copy/design proofing or as final artwork – using different specifications as appropriate.
Standard quality for copy/design proofing
When making pdfs for our clients to check text, layouts etc, we are aiming to create an accurate image at the smallest possible size to email. The standard setting is usually fine – so long as all fonts are embedded (if not, text tends to appear in a typewriter face). Standard settings give us a vastly reduced file for emailing: as an example, a complex magazine spread could be 100Mb in its native Quark XPress or InDesign format but can reduce to 250kb as a pdf proof.
Standard quality is usually fine for web downloads too – again, the smallest possible size is obviously important on the web.
Standard quality can be printed out on any laser printer for checking purposes, but the quality will not be high enough for use as artwork.
Press quality/custom settings quality for artwork
When we supply final artwork in pdf format, we need to ensure that the quality of all the original components is maintained. This means less (or no) compression, which inevitably increases the file size. The same 100Mb native file referred to above will still reduce, but maybe only down to 40Mb. This is obviously much too large to email, but as this artwork will be supplied to a printer, we generally send the resulting files by ftp.
Newspapers and magazines nearly always ask for advertisement artwork in pdf format, which means that the files are generally very stable and the fonts are embedded (publications are generally very strict about fonts – they will not take files and separate fonts for copyright reasons). Advertisements tend to make smaller files than magazine spreads, so can often be emailed, but they still need to be Press Quality. Pdfs made through Word etc will give very disappointing results.
Custom settings for a particular printer or publication can be set up and saved in our Distiller programme – these allow the end producer to precisely specify how they want the file produced for best results.
MORE ON PRINT
- What’s the difference between a vector file and a bitmap?
- Can you give me measurements for US and UK paper and envelope sizes?
- What’s wrong with printing pictures from the web – they look OK on screen?
- What are professional proofing marks?
- Why are some leaflets VAT standard rated and some zero rated?
- What are my options for printed proofs?
- What’s the difference between jpg, eps and tif files?