PDF (Portable Document Format) is the required way that documents need to be sent to us. Once a Design is completed it must be output in PDF format ready to be printed.
Some programmes such as InDesign and CorelDraw have PDF converters ‘built in’ but most programmes do not. However the lack of an ‘inbuilt’ convertor is no bar to producing perfect PDFs and often using an external PDF creator is more reliable.
Later in this article we discuss in detail the setup of two favoured external PDF creators. The first is Adobe Acrobat Professional which is the print industry flagship PDF creation and manipulation programme but has the big disadvantage of costing about £500.00! The second is Desk PDF which is a much more limited programme than Acrobat Professional but we have found creates excellent PDFs and costs around £20.00! Finally we look at the creator built in to the latest Apple system. However before getting in to the specifics of using particular creators there are some general guidelines and pre-requisites to creating reliable PDFs for print:
1) Please read our Designing for print guide before starting your design.
Designing for Print here
2) Flatten layers where possible.
Where designs are built up using a number of transparencies it makes a much more reliable PDF if these layers are flattened. It may be worth saving your original document with the suffix ‘unflattened’ and then saving the flattened document. Remember that if any changes need to be made subsequently you MUST discard the flattened document before re-working the un-flattened version. This will avoid having different editions in the un-flattened and flattened format.
Ultimate flattening means having all the design on a single layer. However this may not be desirable because, in Photoshop for example, text layers must be converted from Vector to Bitmap to merge with picture layers.
The recommended approach is to flatten all bitmap layers to one but leave the text as text. This will give much better quality text in the finished print.
3) Check image integrity
Ensure that all pictures used in the design are either embedded or that the links to external images are correct. Whilst most programmes will warn if a link is missing it frequently happens that a PDF is created containing screen resolution images simply because the correct file was not located. Check that all images used are CMYK and that they are at least 400dpi size for size in the document. Whilst it is perfectly possible to print from lower resolution and RGB images the quality of the finished print will be compromised.
4) Check that fonts can be embedded.
There are a small number of fonts which have licensing restrictions attached. These restrictions can prevent the fonts being embedded in the PDF even if that request is made in the PDF setup. One solution to this perennial problem is to avoid fonts with these onerous restrictions. Another may be to change your design by selecting another font with less onerous restrictions. A third solution available in many drawing programmes is to convert the fonts used in to curves.
5) Check the created PDF looks as intended!!
Whilst the creation of PDFs is normally a foolproof process, it is certain that when it is least expected and most disastrous the process will work poorly. It is absolutely essential to check that the PDFs created look the way they should before sending them to print. The best way to carry out this check is to download the free PDF viewing programme Adobe Reader. This is available free from the Adobe website.
Open your files in Reader and check they view correctly. Check that Bleed and Registration Marks have been carried across to the PDF In addition, ideally, print out each page and check the backup of double sided jobs is correct. Only after carrying out these checks should the PDF files be sent to print!