If you’ve ever been given a list of billboards to create in Indesign, you’ll know that the artwork has to be set up at a percentage of the final size. Usually the specs are given in total width and height for the trim size, bleed size and non image area. This makes it a hassle to calculate the bleed and non image area (as a margin) at artwork size, whatever percentage of final size that may be.
This script makes it easier by asking you for the trim size, visual area and bleed size (all at final size) and then sets up a new document for you at the percentage of final size that you specify. In the case of a non visible area like a frame covering the edge, the document will create a layer with a transparent grey border.