This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Background formed from the original with an emboss effect
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
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
A free light orange brown wallpaper with vertical stripes designed for use as a tiled background on websites. An yet another background pattern with vertical stripes.
Source V. Hartikainen
A seamless background texture of old cardboard.
Source V. Hartikainen
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
A seamless web texture of "green stone".
Source V. Hartikainen