Background pattern 222 (colour 2) #2344
 Brown  CC 0

A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

 More Textures
[email protected] #126
 Dark  CC BY-SA 3.0

And some more testing, this time with Seamless Studio. It’s Robots FFS!

Source Seamless Studio

[email protected] #112
 Dark  CC BY-SA 3.0

Dark pattern with some nice diagonal stitched lines crossing over.

Source Ashton

Floors & Wood #1614
 Wall  CC 0

Floors-Tiles. CC0 License.

Source Unknow

Decorative divider #1995
 Yellow  CC 0

From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.

Source Firkin

Retro Squares Background [email protected] #798
 Noise  CC 0

Retro Squares Background 6

Source GDJ

Leafy pattern 7 #1828
 Dark  CC 0

Remixed from an image that was uploaded to Pixabay by CatherineClennan

Source Firkin

Dark [email protected] #620
 Dark  CC BY-SA 3.0

Continuing the geometric trend, here is one more.

Source Mike Warner

Diagonal Striped [email protected] #680
 Stripes  CC BY-SA 3.0

Might not be super subtle, but quite original in its form.

Source Alex Smith

Subtle Carbon #949
 Dark  CC BY-SA 3.0

There are many carbon patterns, but this one is tiny.

Source Designova

Background pattern 252 (colour 4) #2159
 Light  CC 0

Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Vintage [email protected] #654
 Wall  CC BY-SA 3.0

Lovely pattern with splattered vintage speckles.

Source David Pomfret

Stone Wall & Dark #1521
 Stone  CC 0

Incoming catena. Stone & well. CC0 texture.

Source Unknow

Black Linen [email protected] #104
 Dark  CC BY-SA 3.0

A new take on the black linen pattern. Softer this time.

Source Atle Mo

Grey Sandbag #641
 Paper  CC BY-SA 3.0

A bit strange this one, but nice at the same time.

Source Diogo Silva

Transparent Square Tiles #298
 Grid  CC BY-SA 3.0

The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.

Source Nathan Spady

Vintage Clay Tile 2 #1459
 Unknow  CC 0

Gamedev - Roofs Textures. CC0 License.

Source Davit Masia

Background pattern 309 #1866
 Yellow  CC 0

Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.

Source Firkin

[email protected] #297
 Grid  CC BY-SA 3.0

A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.

Source Josh Green

Planks & Roughcedar #1354
 Wood  CC 0

CC0 for Free, hope you like it.

Source Yethiel

Background pattern 323 (colour 3) #1810
 Yellow  CC 0

Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.

Source Firkin

Banner pack 6 #2438
 Colorful  CC 0

Three coloured banners. From an image on Pixabay.

Source Firkin

Retro Circles Background [email protected] #429
 Noise  CC 0

Retro Circles Background 6

Source GDJ

Asfault 6 #1385
 Dark  CC 0

Gamedev - Asphalt textures. CC0 License.

Source Davit Masia

Wavy background #2023
 Pink  CC 0

CC0 and a seamless pattern from a tile drawn in Paint.net .

Source SliverKnight

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

Paisley Background #495
 Light  CC 0

Paisley Background

Source GDJ

“Transparent” Background [email protected] #494
 Light  CC 0

An emulated “transparent” background pattern, like that of all kinds of computer graphics software.

Source AdamStanislav