Hello Gwpriester,

Thank you for your response. I tried the two attachments you sent and the same thing happened, except that now there are two duplicate images side by side, as your attachments were 500 px as opposed to my original ones which were 1000.
I had hoped that there was an easy way to get P&GD7 to preserve the left side of the graphic as the browser is expanded to the right (as in the original website I referred to). If there is no easy fix I may have to just crop the graphic to get rid of the left (lighter) portion so that the replication of the tile will be uniform, though what I wanted was to duplicate the effect in the current website referred to in my post.