Like from drawing to pdf or other file type?
You can trigger the Convert task to run during a state change...
Or do you want to change the sheet format? Why?
Want to put watermark on drawing saying "Approved" once it gets to that state
Thought to do this by two sheet formats - one with approved watermark and one without.
There is easier method. We have implemented this.
You put a note on the template that is looking for a Custom Property (from the drawing). Let's call this a property a "StateWatermark". By default the value of the property is "NOT FOR PRODUCTION" but in state changes you write the value for drawings for example "FOR PROTOTYPING" or just a " " (space or empty value) to "clear" the note for Approved states.
For the note itself there is a setting to make it appear as a watermark, but do note that prior to 2015 SP1 there are problems printing it with edrawings.
Also do note that that on your SolidWorks files workflow you need to have a "cleanup" routine where you also change the value of the property to original "NOT FOR PRODUCTION" (this is for files that you re-use)