What are the key differences between raster and vector graphics?
Raster graphics are composed of pixels. If you zoom into a raster image, you will notice all the tiny pixels that make up the image.
Vector graphics, on the other hand, are made up of a series of mathematical paths that produce lines and shapes. If you zoom into a vector image, it will always look the same.
Raster drawing is a lot like painting. You can create a number of interesting blended effects using this method, giving you precise control over your colours and gradients.
When inking an outline, you may choose, for example, to paint inside your lines using various colours or patterns.
Vector drawing forms the outline for curves and shapes, which you can freely fill and transform at any point.
When tracing vector lineart, you may decide to alter the size or shape of an eye, for example, or the width of an outline.
It’s easy to make changes as you go using this approach.
Choosing between raster and vector
Knowing which approach to take to your lineart ultimately comes down to a few simple things:
Scaling
Scaling down a pixel image is relatively straightforward, but scaling up can lead to a drastic reduction in quality, leaving you with a graphic that looks blurry or pixelated. This means you will need to know in advance what dimension and resolution you will need to be working with if you wish to print a high quality raster graphic.
Vector graphics, on the other hand, are perfect for physical reproduction. They’re forgiving of scaling changes, their quality never declines, and they’re so clean and simplistic they look perfect on a print design at any size.
The bigger picture
One of the biggest advantages of using vector graphics is their versatility. You can tweak curves and change colours effortlessly as you go. This is especially useful if you need to print a different version of a graphic with a limited or altered colour palette.
Raster drawing, on the other hand, allows you the freedom to immediately alter your outline layer as you like without editing the shape of your drawing.
The fine details
Producing subtle shading and blending effects is best done in raster. Vector graphics need to use a different shape for each shade of colour. Gradients can be applied to vector illustrations, but these are actually raster effects. The same goes for drop shadows and inner glows.
Raster drawings are great for shading and adding intricate embellishments. The ability to fine tune and personalise your colour selection is extremely useful.
Combining raster and vector graphics
Remember, in Affinity Designer you can always use a combination of both. When raster and vector lines come together, you can create pieces that take advantage of the strengths of each approach.