With the Edit Layout dialog you can make changes to your existing poster's settings. You can adjust the size and resolution of the poster itself as well as how many cells and spacing between the cells.
Editing the width and height in this dialog effects the actual size of the poster. The printer margins are not used in this dialog as they were in the New Poster dialog.
The Border property specifies how much space to put between each picture on the poster.
NOTE: If you make changes to your poster any cell expansions that you have assigned in your poster will be reverted back to the single cell size if you change the number of columns or remove any rows. If you resize the overall size of the poster or simply add rows then the cell expansions will be left in place.