A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
The image is a seamless pattern of a fishnet.
Source Yamachem
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
Prismatic Polyskelion Pattern No Background
Source GDJ
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
Number five from the same submitter, makes my job easy.
Source Dima Shiper
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Here's a new background image for websites with a seamless pink texture. It should look beautiful with website themes where light pink background is needed. The background is seamless, therefore it should be used as a tiled background.
Source V. Hartikainen
This is a remix of "flower seamless pattern".I rotated the original image by 90 degrees.This is a seamless pattern of flowers.These horizontal wavy lines are one of Edo patterns which is called "tatewaku or tachiwaku or 立湧" that represents uprising steam or vapor.
Source Yamachem
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green