firstrebel

I thought that may have been the issue. I tried your suggestion and got this:

So I decided the easiest was to make them all the same size. As they are thumbs the small change does not show.

Many thanks.

Bob

I have used the CSS from this W3School page to create an image gallery: http://www.w3schools.com/css/css_image_gallery.asp

It works OK until you reduce the screen size to that of a mobile in landscape layout. The images no longer follow each other in a regular pattern, and gaps appear. This appearance is random on different mobiles.

Bob