Outer Padding and Margins with Masonry / Isotope

Question

I have been struggling with Isotope for a while now. After a few different sittings, I can't seem to figure this one out.

isotope.metafizzy.co/index.html

I'll illustrate my problem with images, but here is the explanation. As you can see on my site,

test.davewhitley.com/not-wp/isotope_test/index.php

I am using isotope with three same-width columns.

If you look at the outer edges of the central layout, you can see that there is some padding, forcing the whole center to be somewhat narrower than the header / footer. I have played with CSS to my heart's content, but I can't figure out how to expand the central gallery to the edges of the div that it is contained it (it is 960px — therefore, the central gallery is about 940px). Normally I could do this with just divs and some CSS, but masonry's javascript is over my head (all of its calculations and such). Any help would be greatly appreciated.

Here is my problem illustrated. What I have:

http://farm7.static.flickr.com/6207/6057816365_e0b6e2e8c4.jpg

What I would like:

http://farm7.static.flickr.com/6208/6058362460_d1200a1491.jpg

Sorry for the linked images and non-hyperlinked text, I am too young on this site.

Solution

See Masonry with gutter width mod for Isotope:

• http://isotope.metafizzy.co/tests/masonry-gutters.html
• http://metafizzy.co/blog/tests-modified-masonry-layouts