What is dithering?
Dithering is a pixel art process used to blend blocks of colour together or help apply a texture to a pixelled surface. Within emoticons it is most commonly used when making pixelled backgrounds, however it can be used in a number of other areas, e.g. massive emote bases, pixel objects etc. In this tutorial, we will focus on how 2 colours can be blended with dithering.
To break dithering down into simple terms, it is achieved by simply taking the colours from the two blocks of colour and placing individual pixels of each on the opposite side. This creates a region where the two colours merge together to create a more blended colour transition instead of a clear line between the two.
Dithering can seem like a complex process, but it's really not. Once you get the basic idea and technique, it's just all about practice and over time you'll learn how to apply it to a number of different situations. There are many dithering styles which can be used to give a different end result. In this tutorial, I will walk you through a basic dithering method designed for dithering larger surfaces, such as background or huge emote bases. Whilst this method has several set steps, this is not the only way to dither and I do encourage you to experiment and find a style you feel comfortable with.
Dithering straight lines
For this style of dithering, the process can be broken down into 4 main steps. Each phase adds more detail to the dithering to give a more even and smooth blend to the colour transition.
Step 1 - Inner layers
Having created your two patches of colour, the first step is to put down a 'inner layer' of dithering. This is a dotted line of pixels right at the dividing line of colour. The pixels should be quite regular as this is the point where the colours should most blend. To get a good coverage it can be useful to place the pixels in a set pattern (e.g. every other pixel).
As you go further and further away from the colour split, the amount of pixels you use should decrease to help give a nice blend in and out of the dithered region. This can be achieved by changing your pattern. e.g Place a pixel of colour every other pixel on the first row, every 4 pixels on the second row, every 8 pixels on the third row etc.
Another good idea is to make sure that you don't clump pixels together. To give a nice even spread it works best to place a pixel in a position diagonal to the last, rather than directly up, down, left or right. This helps to mix the two colours together and no create spots of colour that stand out too much.
The size of the inner layer you use should depend on the size of the colour blocks you are blending. With a small gap, fewer layers should be used. If the distance is larger, you can increase the amount. A lot of this comes down to practice, experimenting and your personal preference.
Step 2 - Outer layers
Once you have used as many inner dithering layers as you feel is appropriate, it is best to add another layer of dithering that is far more spaced out to help make a smother and more gradual blend. To achieve this, it is best for the pixels not to touch any others in the area to prevent them becoming an extension of the inner layers.
Step 3 - Random noise
After completing the stages above, the end result will look quite rigid and structured. Whilst this style of dithering is useful in some pieces of art, the 'real world' isn't usually perfect and adding in a few random pixels can help make the dithering look more natural.
Step 4 - Mirror
Dithering should be applied on both sides as only pixelling in one direction will still leave an obvious dividing line. Once you have finished steps 1-4 on one side of the line, simply repeat on the other to complete the blending of colours.
Hints and Tips
It can be quite boring and tiresome to dither a large region all by hand. You can therefore take some slight shortcuts with straight line dithering and reuse sections. Having dither a length, simply copy and paste it to repeat it on the same line, on the mirror of the side, or on a different patch of blended colour.
If you opt to reuse patches of dithering, try and make sure that you don't lose and randomisation you have included. If you only dither a 10 pixel region and repeat it, it will again look quite structured. It is far better to repeat regions of 40+ pixels so it is less obvious.
Dithering around circles and curves can be a little harder to get the hang of. Whilst the principle is the same as straight line dithering, the method changes slightly and relies a lot more on 'going with the flow' and working with each individual case, rather than using a set pattern.
Step 1 - Inner layers
Once again we start by adding in a layer of pixels directly on the colour change line which are linked together on the diagonals. It is never easy to work to a set pattern, so it is best to judge each part of the curve separately. The pixels should be added in a diagonal position to any existing ones to help create a nice blend of the two colours, rather than solid blocks with a wavy edge. It is also a good idea not to add a pixel on every diagonal position, or you can demolish and rounded edges by squaring them off with dithering.
Step 2 - Outer layers
Having added the inner layers, you should again add some outer layer pixels, which aren't directly connected to any of the pixels already in place. these can also be useful to help round off the shape and back a circle appearance that the inner layers may have hidden.
As the placement of pixels on a rounded circle ends up being more random due to the lack of pattern, additional 'random noise' isn't really needed as the outer layers offer this.
Step 3 - Mirror
It is especially important to remember to dither on both sides of the diving line when shading a rounded edge. When working on the inside curve, it is important that you don't bunch up the pixels too much as it will affect how well the colours blend.
Different dithering styles
The examples above give details on one method of dithering. However, there are many different styles used by the community, and there is nothing wrong with modifying or ignoring some of the stages to create your own style. To help show off some of the other styles in the community, I kindly asked a number of emoticonists to dither a sample of their own dithering to give some example of other end results.
Hover for artist's names
General hints and tips
Colour choice is very important when you work with dithering. The colours you use should contrast enough so that the dithering is noticeable when you zoom out. However, be careful not too go too far the other way and make the contrast too large that the colours wont easily blend. A lot of it is simply down to practice and experimenting.
Too little | About right | Too much
Don't forget to apply dithering at the top and bottom of the canvas. Sometimes the boundary of a colour block can lie on the border or just outside the edge of the canvas. It is important to dither these areas as if the canvas is never ending, or the top and bottom sections will look out of proportion to those with dithering on both sides. Alternatively offset the colours so no colour dividing lines are near the edge.
Without | With
To help make the patterns more obvious when dithering, try using random bright contrasting colours during the dithering process and re-colouring them once you are happy with the dithered pattern.