OUGD504- Format Research

- Always save files at 300dpi when printing!

Here are a few of the most common formats and why you may or may not want to use them:

File Formats 

TIFF
- This targeted file format is the highest quality and is excellent for print as there is no loss in quality.
- Retains information in layers, depending how you save it.
- The downsides are the extremely large file size and you cannot display on the web in this format.
- Lossless format so you will retain information from your images as you re-open and re-save.

JPEG
- The Joint Photographic Experts Group format is the most common type. It is viewable by all and can be used for print and the web.
-When saving as a jpg, you decide what quality you desire (In Photoshop for example a level 1 is the lowest quality or a 12 which is the highest quality)
- The biggest downsize is that the jpeg format is lossy. Each time you open and save, the image compresses and you lose a small amount of information.
-Another downside is that layers are flattened upon saving so you lose the ability to go back to past edits to tweak.

PNG
-The Portable Network Graphics format also creates smaller file size but without the quality loss of a GIF.
-Useful if you need to maintain transparency.
-Often used for graphics instead of GIF.
-Lossless format so you will retain information from your images as you re-open and re-save.
-You can share these files on the web.

PDF are the best format to send files to external printers

-Portable Document Format preserves document formatting and enables file sharing. 

-When the PDF format file is viewed online or printed, it retains the format that you intended. 

-The PDF format is also useful for documents that will be reproduced by using commercial printing methods.


Files for other files

A lot of the files you create will be embedded or imported into something else, like Indesign.

Two categories: -vectors and bitmaps 

Vectors

Even at 300dpi the TIFF and JPG don't handle this vector graphic nearly so well. They have to convert it to pixels, and in this situation it shows.

In this photo from the Print Handbook you can see why PDFs and EPSs trump TIFFs and JPEGs every time for vector stuff.

You are best off saving vector artwork as an:

-EPS 

-PDF  

-AI file 

Bitmaps

-TIFFs 

-JPEGs 

-PSDs 

are what you should be saving your bitmap files as

TIFFs and PSDs are lossless. You don't lose any quality by saving a file as a TIFF or PSD.

JPEGs normally lose quality when you save them but take up a lot less space on your computer. A very high quality JPEG is often not a lot different to a TIFF or PSD, but it does very much depend on the sort of image you're saving.

A TIFF or PSD is normally a better option than a JPEG. But if you've been supplied with a JPEG, from a camera or stock photo website, and you're not modifying the image then you will gain nothing from saving it as a TIFF or PSD. 

A TIFF or PSD cannot create detail where there was none in the first place. But a JPEG can remove detail where once there was some.

There's a couple of thing to notice in the pictures here related to JPEGs. 

Firstly, JPEGs can't handle spot colours. So when this JPEG was saved it converted the Pantone colour into a CMYK value. 

Secondly, the white space in between the red lines on the JPEG is filled with a very subtle yellow/grey tint. This is due to the compression.