Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
Geometric triangles seem to be quite hot these days.
Source Pixeden
A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.
Source V. Hartikainen
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 bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Prismatic Curved Diamond Pattern No Background
Source GDJ
Abstract Tiled Background Extended 8
Source GDJ
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Used a cherry by doctormo to make this seamless pattern
Source Firkin
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev