Dark Brick Pattern #1032
Stone CC BY-SA 3.0A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
More Textures
Small Crosses #115
Stripes CC BY-SA 3.0Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Carbon Fiber #3
Carbon CC BY-SA 3.0A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
Prismatic Hexagonalist Pattern No Background #390
Light CC 0Prismatic Hexagonalist Pattern No Background
Source GDJ
White Well & Fissure #1701
Wall CC 0Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
Decorative divider #1962
Dark CC 0From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
Wavy background #2015
Green CC 0A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Strange Bullseyes #865
Light CC BY-SA 3.0This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
Paper 2@2X #22
Paper CC BY-SA 3.0New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
Tessellation 16 #2215
Yellow CC 0The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Nasty Fabric #1008
Gray CC BY-SA 3.0Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Prismatic Rounded Squares Grid 4 No Background@2X #492
Noise CC 0Prismatic Rounded Squares Grid 4 No Background
Source GDJ
Well #1261
Wall CC 0Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Joined spirals pattern #2482
Yellow CC 0The starting point for this was drawn on the web site steamcoded.org/PolyskelionMaker.svg
Source Firkin
Wavy background #2022
Blue CC 0CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Absurdity #825
Light CC BY-SA 3.0Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Metal Grid Pattern #1091
Metal CC BY-SA 3.0A repeatable image with dark background and metal grid pattern.
Source V. Hartikainen
Background Pattern Green #1939
Green CC 0Fix and cc0 to get the tile this is based on.
Source SliverKnight
Micro Carbon #7
Carbon CC BY-SA 3.0Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Arches #715
Light CC BY-SA 3.0One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Paper Fibers #1060
Paper CC BY-SA 3.0Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Textured Paper Background (Vanilla Yellow) #1219
Yellow CC BY-SA 3.0Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
White tiles@2X #728
Grid CC BY-SA 3.0A nice and simple white rotated tile pattern.
Source Another One
Pixel Weave@2X #1155
Unknow CC BY-SA 3.0Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran