An Introduction to the Photoshop Brush Engine

Open a new blank file where you will be able to test your new brush.

Select the Brushtool (or press B) and than click on the “Toggle the Brushes palette” button that is shown on the image on the right (or press F5).

The window that opens is the brushes palette. Here you will create and edit your brushes.

Some of the modifications you do with a brush are based on so called jitters. jitters can work in 2 different ways.

• 1. A jitter can randomly change a certain value, like the size of the brush, for every brush mark, that is drawn. To use a random jitter just slide up the scroll bar below it.

• 2. In addition a jitter can modify a value with fade or by pen pressure, pen tilt or the stylus wheel. To select one of these choose it from the drop-down menu Control.

If you choose a control, your graphics pad doesn’t support, there will be an exclamation point left of the drop-down menu warning you.

• Fade is the only one of these four values, that doesn’t depend on a graphics tablet. It just increases the value it’s used for with every mark of the stroke you draw, until it reaches the minimum value. How many marks are drawn is determined by the number next to the drop-down menu.

• Pen Pressure is the classic setting and supported by most graphics tablet. It let the value it is used for depend on how much you impress your stylus.

• Pen Tilt is measuring the angle in which you hold your stylus to the graphics tablet. The straighter you hold it, the bigger this value will get. The more you pitch it towards the tablet the smaller it gets. Pen pressure is only supported by the more improved graphics tablet like the Intuos or Cintq Series.

• Stylus Wheel resembles a mouse wheel and comes only with the Wacom Intuos Airbrush Pen. Turning the wheel will modify the value while you are drawing. This is for example great to adjust the size of your brush.

• Some Jitters also have a minimum, which determines the smallest value this jitter can create (for example the smallest brush size). The maximum of a jitter depends on the original value of the option that is jittered. If for example your opacity is set to 50% and the minimum opacity is set to 20%, an opacity jitter can only create brush marks with an opacity between these two values.

This is were you really start to set up your own brush. In the top of this menu you can choose the basic shape of your brush. This can be a simple circle, a square or a more natural shape by using a sampled image.

• The Diameter is just the basic size of your brush that can later be changed as always.

• Flip X and Flip Y is only of interest if you are using a asymmetrical brush. It will flip the texture of it.

• Angle turns your brush.

• Roundness compresses the shape of your brush by specifies the ratio between the brush’s short and long axes. If you are using a round brush it gives you an ellipse. For any other brush it just makes it smaller in one axis.

• Hardness can only be used for the standard round or elliptic brush, not for sampled brushes. Decreasing the hardness will blur the edges of the circle, giving you a softer brush.

• Spacing is a good way to see how the brush engine of Photoshop works. Increase the spacing and the single brush marks will be drawn apart. The smaller the spacing, the more the brush marks will overlap each other. If you are just working with a round brush it is the best to decrease the spacing but when working with a textured brush this could probably cause a overlapping of the texture. If you are having performance issues you can also try to increase the spacing. Deactivating Spacing will make the space between the single brush marks depend on how fast you move the brush.

With Scatter the position of you brush tip is randomized around its original position. If Both Axis is enabled every single brush mark will be randomly scattered around a certain radius depending on the scatter. If Both Axis is disabled it will only scatter in the right angle from your line. If you choose a control for scatter you must set it higher then 0%, otherwise it won’t do anything.

If you increase the Count there will be more Brush marks scattered around every spacing interval of the stroke. This value makes only sense used in combination with scatter. It works different than spacing. Because spacing determines how much space is left between every interval. The count determines how often your brush marks is drawn on each of these intervals. Without scatter all these brush marks of one interval would be drawn over each other.

The texture menu gives you the possibility to add more structure to you brush, by laying a texture over your brush.

• The small graphic at the top is the texture that will be used.

• Scale determines how big the texture will be. This is independent from your brush size. The scale of the texture will always be the same, no matter how big your brush is. This allows you do create some kind of canvas effect with texture.

• Mode defines in which way the texture will be laid over your brush. It is hard to explain the different modes, so its best to try them out. I like Hard Mix.

• Depth lets you adjust how strong the texture will affect your brush. A maximum depth can lead to spots of no opacity in your brush while no depth won’t affect your brush at all.

This is the most complex option, but also offers you the most interesting effects.

In this menu you can choose a second Brush and define certain properties for this brush (they work the same way as for a normal brush).

This Brush then will be overlayed in one of the same modes as you could choose for texture over your original brush.

The effects that can be created by this menu are heavily effected by what combination of brush tips you choose, what mode you choose, but also scattering one or both of the Brushes influences the outcome. You should just play around with the options and try different combinations.