# Top Bar
You can easily change basic brush settings here.
 The floppy disk icon is there to save your Texture 2D.
 These arrows will undo / redo your actions. Shorcuts are [Ctrl+Z] and [Ctrl+Shit+Z] on
Windows / [Cmd+Z] and [Cmd+Shift+Z] on Mac. These shortcuts can also be changed in Unreal Engine Preferences, in ILIAD tab.
At the moment, Undo / Redo will only affect strokes on the canvas.
You won’t be able to Undo / Redo actions on the Layer Stack or in Brush Exposed Parameters, for instance.
 The eraser is a toggle to activate with [E]. I turns your current drawing tool into an eraser.
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**Size** (in pixels) : Make sure the node “Get Size Modifier” is well-used and connected to nodes like “Resize” or “Resize Uniform” in your Odyssey Brush blueprint (see the Odyssey Brush section)
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**Opacity** (in %) & Flow (in %) : These options seems to be the same, but they really are different. What is the difference between both ? If you lower the opacity, your stroke will never get beyond the limit. If you lower Flow, your stroke will be more transparent, but if you pass by the same zone, the stroke will get opaque.
*Opacity 25% :*
*Flow 25% :*
If Opacity does not need to be connected to your stamp, this is not the case of Flow. Make sure the nodes “Get Flow” is connected to your stamp (see the Odyssey Brush section).
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**Blend modes** : This mode is used to blend pixels on the canvas with pixels applied with your Odyssey Brush.
*Normal Blend Mode :*
*Multiply Blend Mode :*
*Add Blend Mode :*
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**Alpha modes** : This mode affects the Alpha channel of your brush (which means the opacity / transparency of the stamp used in your brush) and gives it a specific property.
*Normal Alpha Mode :*
*Erase Alpha Mode :*
*Back Alpha Mode :*
Iliad User Documentation 
