A blog post about file types? Yawn. Clean, crisp and colour-correct imagery in a book? Now we’re talking. Every project we work on at Hyphen is different, but they often encounter similar issues when it comes to imagery. Here is a quick run-down of all you need to know when it comes to using and sharing files.

Raster vs Vector

All images can be defined as raster or vector.

Raster images are made of pixels and are resolution-dependent. Scale them up too much and they lose clarity. All photographs and scanned images are raster, and they make up most of the images we work with at Hyphen. The most common types we see are JPEG, PNG and TIFF.

Vector images are made using maths rather than pixels, which means they can be resized to any size without losing sharpness. They’re typically used for logos, icons and illustrations. Brands often have a suite of these graphics. They’re sometimes supplied as standard image files, but wherever possible, it’s best to provide the original vector files (AI or EPS). That way, they can be edited without distortion.

DPI and PPI

DPI and PPI measure image density. DPI stands for Dots Per Inch and refers to the ink drops applied during print. The higher the number, the more ink droplets are tightly bunched together and the more detail you will see. PPI stands for Pixels Per Inch and works the same as DPI, but it is used in the digital space, referring to the pixels displayed on screen.

At Hyphen, we work predominantly in the print space and so are most concerned with DPI. Taking DPI one step further, InDesign shows us an image’s Actual DPI and Effective DPI. Actual DPI refers to the DPI of the file in its original size and format, whereas Effective DPI changes based on scale. This is important to note because even if an image appears to have a high DPI, it will not maintain this quality once scaled 200 per cent. We always request large scale, high DPI images for things like chapter openers, cover designs and full-page hero images.

There are ways around a low DPI. Photoshop is great for manipulating imagery and can be used to scale up an image. Depending on the nature of the image, this can work quite well. Other times it adds a soft blur to the image and looks obviously wrong.

File sharing

There are plenty of great resources available online for file sharing. Our preference is Dropbox, however we understand that clients may have restricted access to various sites, and we are always happy to work with the programs that our clients prefer. The best thing for us is consistency within a project. This ensures nothing gets missed as the files file in.

Are we really still talking about files?

I know it may come as a surprise, but there are many more things to be said about file types; like what the file extensions stand for and what the difference between linked and embedded files are. But I think we have reached the file chat quota for today, don’t you?

– Jane Heriot, Junior designer