If you need a green background for your blog/website, try this one. Remember that Green Striped Background is seamlessly tileable.
Source V. Hartikainen
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
A nice and simple white rotated tile pattern.
Source Another One
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
It’s big, it’s gradient—and it’s square.
Source Brankic1979