Pixels vs. Vectors

Two types of files

Technically, in the graphics world, you have roughly two types of files for images, photos, and illustrations: pixel and vector graphics. Before we share a handy trick with you how you can easily see the difference in pixels or vectors for yourself, let's get some explanation.

1. Pixel graphics

Pixel images include jpg, png, tiff and psd files. This can include logos, illustrations, graphics or photos, for example.

These consist of all small, square blocks (pixels), each with its own color. As you zoom in on your image, they all become larger and more visible. That is why the 'resolution' is very important for these types of files.
The resolution is indicated in PPI (“pixels per inch”), but DPI is also often used to indicate the resolution (“dots per inch”). This is the number of pixels per 2.54 cm (= 1 inch) in height and width. The more pixels per inch, the finer the image and the higher the resolution. (And the bigger the file gets!)

The resolution for a display (low resolution is sufficient) are different from the requirements for printing (high resolution is required).
• Coarse pixels = low resolution, for example 72 dpi, only suitable for monitor and online use.
• Fine pixels = high resolution, e.g. 300 dpi, suitable for printing

When you inflate a low-resolution image to a large format, the individual pixels become visible and thus your image becomes “pixelated.” A pixel file smaller than 1 Mb (e.g. a photo) is therefore often not suitable for use in a very large format.

2. Vector graphics

Vector images include eps, ai, and svg files. This can also be logos, illustrations, graphics, but never photos (these are always pixel files).

In vector images, the shapes and/or letters consist of a number of fixed points with (circumferential) lines in between. These “paths” are straight or curved segments defined by mathematical vector numbers. The resulting lines and surfaces have a certain thickness and/or fill of a certain color, or sometimes several. This ensures clean shapes and lines.

Because of this structure, the resolution does not play a role in vector images. When resizing this type of image, the points and paths are scaled proportionally and the shapes and lines maintain their tightness and sharpness. There is no loss of quality. This means that they are better suited to use in large publications in particular. But even for small-format use, it is always better to use a vector image than a pixel image. And that's why we prefer vector files to work with rather than pixel files!

What should I pay attention to then?

When submitting files, you can look at the file extension anyway. JPG, png, tiff and psd files are pixel images and can therefore not be enlarged indefinitely. In addition, it is also good to pay attention to the resolution. For online communications, a low resolution (coarse pixels), or 72 dpi, is often fine. For printing, you really prefer to use a high-resolution image (fine pixels) of 300 dpi or higher. Okay, we can sometimes still mess around with small-format digital printing, but above 150 dpi is actually a must. The size of a pixel file is also indicative: photos should be at least 3 to 4 Mb for use in small print; and you shouldn't expect much from a 40k logo...
Vector files often have an eps, ai, or svg extension. When you see that, you can usually scale the image very easily. So please provide logos and illustrations as a vector file. That gives us more options and then you can be sure that you will always get a sharp result!

Catch

But note: sometimes it looks like something is a vector file because it has the correct extension (EPS, AI, SVG); however, it may be that it is secretly a pixel file. This is because a pixel image is then placed in a file that is then saved with a vector extension, such as eps. But unfortunately, that doesn't spontaneously turn it into a vector image. It remains a non-scalable pixel image and is usually not useful.

Check, check, double check

You can test quite well for yourself whether you are dealing with a pixel or vector image. Zoom in on it quite a bit. What's happening? Will the picture stay just as sharp? Then it's probably a vector image. If it gets pixelated and out of focus, you're dealing with a pixel image. This way, you can easily find out the difference between pixels and vectors!