Random Grey Variations@2X #70
 Stripes  CC BY-SA 3.0

Stefan is hard at work, this time with a funky pattern of squares.

Source Stefan Aleksić

 More Textures
Smooth Wall #27
 Light  CC BY-SA 3.0

Some rectangles, a bit of dust and grunge, plus a hint of concrete.

Source Atle Mo

Subtle Striped Brown Background Pattern #940
 Stripes  CC BY-SA 3.0

Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.

Source V. Hartikainen

Spotted Light Yellow BG Pattern #1216
 Yellow  CC BY-SA 3.0

This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.

Source V. Hartikainen

Soft Kill #318
 Dark  CC BY-SA 3.0

Pattern #100! A black classic knit-looking pattern.

Source Factorio.us Collective

Carbon Fiber v2@2X #106
 Carbon  CC BY-SA 3.0

One more updated pattern. Not really carbon fiber, but it’s the most popular pattern, so I’ll give you an extra choice.

Source Atle Mo

Floral Seamless Pattern Background #261
 Fabric  CC 0

PDP

Source GDJ

Fabric pattern 3 (colour 5) #2383
 Fabric  CC 0

Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Background pattern 24 #198
 Dark  CC 0

The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.

Source Firkin

Black Scales #191
 Dark  CC BY-SA 3.0

Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.

Source Alex Parker

Background pattern 306 (colour 2) #1881
 Colorful  CC 0

Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.

Source Firkin

60º lines@2X #26
 Light  CC BY-SA 3.0

Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.

Source Atle Mo

Soft Circle Scales@2X #114
 Light  CC BY-SA 3.0

Japanese looking fish scale pattern.

Source Ian Soper

Real Carbon Fiber #286
 Carbon  CC BY-SA 3.0

Carbon fiber is never out of fashion, so here is one more style for you.

Source Alfred Lee