A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
A nice and simple white rotated tile pattern.
Source Another One
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868.
Source Firkin
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
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 seamless web background with texture of aged grid paper.
Source V. Hartikainen
Seamless Light Background Texture.
Source V. Hartikainen
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin