DPI and PPI

The more dots per inch, the better quality the printed image will be.

Resolution is another key term that is often confused. There are two main acronyms used when dealing with resolution: DPI and PPI.

The first is only of concern when you’re creating work for printed output. It stands for ‘Dots Per Inch’ and refers to the number of dots per inch on a printed page. Generally, the more dots per inch, the better quality the image – and 300DPI is the standard for printing images.

PPI refers to ‘Pixels Per Inch’ and, as you’d expect, is the number of pixels per inch in your image. If you resize an image in Photoshop – making it larger – you will increase the number of pixels per inch (with Photoshop making up the data) and you will lose quality. Bear in mind that resolution only applies to raster graphics – because vectors do not work in pixels.