A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Prismatic Abstract Line Art Pattern Background
Source GDJ
Prismatic Triangular Background Design Mark II 5
Source GDJ
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
If you need a green background for your blog/website, try this one. Remember that Green Striped Background is seamlessly tileable.
Source V. Hartikainen
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev