Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
Sharp but soft triangles in light shades of gray.
Source Pixeden
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
A version without colours blended together to give a different look.
Source Firkin
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen