6 key terms every graphic designer should know

Whether you're a newbie, a student or just in need of a refresher, read this guide.

Graphic design, like any profession, is littered with jargon and terms you may not be familiar with. Here are just some of the key terms you should know, and a brief explanation in words you can understand - plus where to go to learn more.

So whether you're a student or beginner, or just need a refresher course, read on...

01. Raster images and vector images

Vector-based images (like this one) are made of points; raster images are made of pixels

Raster images (sometimes referred to as bitmap images) are made up of thousands of pixels which determine the colour and form of the image.

Photos are raster images. Photoshop is the most common raster editor, enabling you to manipulate the colour and other properties of the pixels. But, because raster images are made up of a finite amount of pixels, resizing can be tricky. If you make a raster image larger dimensions in Photoshop, the software has to make up data in order to add the size. This results in loss of quality.

Vector images

Vector-based images (such as those created in Adobe Illustrator) are made up of points, each of which has a defined X and Y coordinate. These points join paths to form shapes, and inside these shapes you can add colour fills. Because everything is generated based around this, vectors can be resized to any size without any loss of quality.

In recent times, Illustrator has progressed so much that vector graphics have become incredibly complex - and you can now add gradients, complex shapes and more to create highly detailed, scalable vector images. Because vectors can be resized, they are often used for creating logos and other graphics that need to go across many different outputs (from leaflet to billboard, for instance). For more details see our articles Get started with vector illustration and How to create vector art: top tutorials.

02. CMYK and RGB

CMYK stands for Cyan, Magenta, Yellow, Key

CMYK is the standard colour mode for sending documents - be it magazines, newspapers, flyers, brochures, annual reports and so on to the printers. It stands for Cyan, Magenta, Yellow and Key (or black - key because in four-colour printing, cyan, magenta, and yellow printing plates are carefully keyed, or aligned, with the key of the black key plate). When you send a job to the press, cyan, magenta, yellow and black plates are made (on a traditional press, anyhow) and then aligned to print on paper. You can add Pantone, or fifth colours, which are created as separate plates.

When working in Photoshop or Illustrator, you have the option to set your document's colour mode as CMYK, RGB (red, green, blue - for screen output) or other colour modes (but the former pair are the two you really need to know about). For more on colour systems, read this article.

Because CMYK has a more limited colour gamut than RGB (which is essentially what the eye sees and how screens output) you can experience a loss of colour when converting from RGB to CMYK in these applications.

03. 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 former 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. There's an excellent explanation here.

Bear in mind that resolution only applies to raster graphics - because vectors do not work in pixels. And for a comprehensive guide to printing terms, this app will serve you well.

Next page: three more key terms you should know