This filter acts as if the design is being boosted or squeezed. It expands and stretches it from the centre. When lightly applied, the filter can be used to subtly change small features of the design, especially when used in conjunction with the Pin Tool.
Instructions
- Open the Filter Browser, and add a new filter set using the small + icon located in the middle of the browser. This will create a new ‘untitled’ filter set for you. This will appear in the top section of the Filter Browser. If you already have filter sets created, clicking the + button will duplicate the selected filter set.
- Select Bump Distortion from the list of available filters in the lower section of the Filter Browser
- Double click on the name of the new filter set in the top section of the browser, and name it appropriately
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Edit the variables to achieve the result you need
- Radius - controls the diameter of the bump effect
- Scale - controls how zoomed the effect is
- Centre - specify a new origin using a pin or selection. Without selecting one of these options, the centre of the effect will be the centre of the design. To learn more, go to the next tab - Using the Centre options
This filter is perfect for preparing a woodgrain design to have additional knots added to it, as it warps the grains. 
Using the Centre options
The origin of the effect applied by this filter will be the centre of the design, unless you specify a new origin using a pin or selection.
Around a pin
- Select the Pin Tool from the Tools Palette
- Click in the area of the design you want to apply this effect around. This will place a pin in that area.
- Edit the variables of the filter until you achieve the effects you need, and use one of the three options described in the next tab to apply the filter
In relation to a selection
- Draw a selection around the area you wish to apply the filter, and press the Selection button under the filters variables. The new origin will be shown in brackets underneath, and the effect will now be centred within the selection.
Clearing the Centre options
- Press the X at any time to clear the new origins.
Applying the filter
There are several ways to apply a filter:
- Click Apply - this will apply the filter to the active layer(s), and within a selection if there is one present in your file
- Click Make Layer - this will make a new layer in your file containing the filtered effect, leaving the original layer untouched
- Apply the filter using the Brush Tool - when you have finished building your filter set, simply close the Filter Browser. Then, open the Brushes Library, and select the filter you have just made from the drop down menu shown in the snapshot below. You can now paint with your filter.
Note: The default setting for the Brush Tool is ‘Brush”, located at the top of this drop down menu. To prevent you from becoming confused between the default setting and a filter setting, do not name any filters ‘Brush’. When you have finished painting with your filter, set the drop down menu back to the Brush setting, otherwise the Brush Tool may not behave as you would expect later on.
Applying the filter over a repeat join
The Bump Distortion Filter works perfectly over repeat joins. The nature of this filter means it is usually applied using the pin or selection method described in the previous tab.
If the pin or selection is placed over a repeat join, the filter will work correctly in repeat, with no obvious repeat joins.
Note: In the image above, the vertical line indicates the repeat join.