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File Formats

’Save As…’.  Yes?  Save as WHAT?!

We are bombarded with suffixes in this age of computers.  A files MUST have a format, a dot-somethingorother.  Without it the computer cannot process it, though it may not actually be displayed to the user, depending on the system you use.

 

Programmes

The programme in use usually dictates the format of the file, though most programmes allow you to ‘export’ a file in various formats.  The ‘native’ format of a file will tell the recipient (the designer or the printer, in this case) which programme was used to create it, e.g. a .psd is a Photoshop file (PhotoShop Document).  If a design or layout has been produced properly, using the appropriate software, the native format will let the printed know that it has at least been STARTED properly.  For example, if we are sent an .indd file (plus any included fonts and images) we expect a design layout, such as a brochure or a flier.  If we receive a .jpg we expect a single, photographic image.

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Formats

This is a list of the common ‘native’ formats and their parent programmes:

.indd = InDesign

.psd = Photoshop

.ai = Illustrator

.doc = Word*

.xls = Excel*

.ppt = PowerPoint*

*most Microsoft Office documents made by the latest software have an extra ‘x’ after the format, e.g. .docx

 

These are the universal formats which can be used by various programmes and are chosen according to the content and use of the file:

.jpg = photos for general use

.tiff = photos at maximum quality

.raw = a specialist photographic format straight from high-end cameras

.eps = vector (sometimes raster) artwork, such as logos

.png = web and screen graphics with transparency

.gif = as above but for simpler graphics

.pdf = final artwork, including layouts, logos, text, images, etc.

 

Some more detail

Photos are usually taken in, supplied and printed as JPEGs.  ‘JPEG’ stands for Joint Photographic Experts Group and is what’s known as a ‘lossy’ format, meaning that some image data is lost at the extreme ends of the spectrum in order to save space used by extraneous information which is not really noticed anyway.  This concept is similar to MP3 music: it will reproduce MOST of the information you’re likely to be able to hear, but the difference WILL be noticed on a good system.

Because of this, JPEGs should be saved at maximum quality and at at least 300dpi, preferably 600dpi at the actual size at which you intend to print them.

The photo format preferred by printers and photographers is TIFF, or Tagged Image File Format, which is ‘lossless’.  This will produce larger files but better quality and that quality will not be reduced every time the file is opened and re-saved, as it is with JPEG.

Of course, we can accept files in PSD (Photoshop) format, but these are often very large and we only really need them if we are to edit any effects, layers or text you’ve applied to the design.  Remember that Photoshop is NOT a design programme and does not reproduce text well.

Another common format is PNG, or Portable Network Graphic.  The clue is in the title here and PNG is intended for website and other screen images.  They are superior to JPEGs for this as they are lossless and support transparency, but that does not make them a print format.  They also save in RGB only and will have to be converted for print.  It’s always best to do this yourself so you can see any changes in colour as they happen.  For GIF (Graphic Interchange Format) images, see above.

We can also accept RAW images, which are used by professional photographers to encapsulate ALL of the data captured by their high-end cameras, with maximum detail and colour range.  These will have to be converted to CMYK for printing and so, again, it’s best that you do this yourself to be sure of the outcome.

Checklist:

  • JPEG for general images, but use max quality and 300-600dpi
  • TIFF for maximum quality but larger files
  • PSD for maximum editing ability but larger files again