Differences, found in Edit Menu > Select, is used to show you what is different between two versions of the same file.
To use the feature:
- Open the two documents you wish to compare. for the function to work, these documents must be the same size and contain the same number of layers.
- Go to Edit Menu > Select > Differences, you will be asked to select a source document to compare your document with, select the appropriate document and press OK.
- A selection will appear on your first document in areas that are different in the other, see example below.
In the example above, you can see one plank is selected, you can just about see that the colour of this plank is slightly different, this is possibly where someone has applied a gamma to change the tones. If you were to get no selection it would mean that the documents are the same.
This function can be useful if you get updated separations back from an engraver and you want to see what the changes are compared to the previous version or you might just have two versions of the same file and have forgotten what was changed in them. This feature is looking for changes in the pixels, it will not tell you if a Spot layer's colour has been changed or more colourways have been added etc.