Green [email protected] #92
 Dark  CC BY-SA 3.0

The green fibers pattern will work very well in grayscale as well.

Source Matteo Di Capua

 More Textures
Dungeons & Flagons 3 #1419
 Diamond  CC 0

Gamedev - Floors Textures. CC0 License.

Source Davit Masia

Bark #1291
 Wall  CC 0

Zero CC tileable bark texture, photographed and made by me. CC0

Source Sojan Janso

[email protected] #754
 Light  CC BY-SA 3.0

This is so subtle you need to bring your magnifier!

Source Carlos Valdez

Textured [email protected] #1131
 Paper  CC BY-SA 3.0

You know I love paper patterns. Here is one from Stephen. Say thank you!

Source Stephen Gilbert

Planks & Wornboards #1350
 Wood  CC 0

CC0 for Free, hope you like it.

Source Yethiel

Floral background 5 #2404
 Fabric  CC 0

A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.

Source Firkin

Stone Wall & Yellow #1572
 Stone  CC 0

Incoming catena. Stone & well. CC0 texture.

Source Unknow

Green Fibers #91
 Dark  CC BY-SA 3.0

The green fibers pattern will work very well in grayscale as well.

Source Matteo Di Capua

Beige Stripes #938
 Stripes  CC BY-SA 3.0

A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.

Source V. Hartikainen

"Polished Stone", Gray Background Pattern #1053
 Stone  CC BY-SA 3.0

A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).

Source V. Hartikainen

Wavy background #2021
 Pink  CC 0

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

Source SliverKnight

Floors #1593
 Wall  CC 0

Floors-Tiles. CC0 License.

Source Unknow

Dungeons & Flagons 10 #1426
 Diamond  CC 0

Gamedev - Floors Textures. CC0 License.

Source Davit Masia

Stone Wall & Dark #1547
 Stone  CC 0

Incoming catena. Stone & well. CC0 texture.

Source Unknow

Retina Dust #915
 Light  CC BY-SA 3.0

First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.

Source Atle Mo

Tiny Grid #891
 Light  CC BY-SA 3.0

You know, tiny and sharp. I’m sure you’ll find a use for it.

Source Atle Mo

Floral background #1964
 Dark  CC 0

Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.

Source Firkin

White [email protected] #132
 Light  CC BY-SA 3.0

Not the most creative name, but it’s a good all-purpose light background.

Source Dmitry

Wood Chips 1 #2099
 Unknow  CC 0

CC0 textures, backgrounds.

Source SliverKnight

Stone Wall & Yellow #1579
 Stone  CC 0

Incoming catena. Stone & well. CC0 texture.

Source Unknow

MBossed #193
 Grid  CC BY-SA 3.0

Embossed lines and squares with subtle highlights.

Source Alex Parker

Fabric pattern 2 (colour 4) #2393
 Fabric  CC 0

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 308 (colour 3) #1870
 Colorful  CC 0

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

Source Firkin

Decorative divider 277 #1906
 Colorful  CC 0

Vector version of a png that was uploaded to Pixabay by pencilparker

Source Firkin

Clean [email protected] #738
 Fabric  CC BY-SA 3.0

A nice light textile pattern for your kit.

Source N8rx

[email protected] #718
 Dark  CC BY-SA 3.0

Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.

Source Janos Koos

Concretia 7 #1414
 Gray  CC 0

Gamedev - Concrete Textures. CC0 License.

Source Davit Masia

Embossed [email protected] #732
 Paper  CC BY-SA 3.0

One more from Badhon, sharp horizontal lines making an embossed paper feeling.

Source Badhon Ebrahim