Prismatic Groovy Concentric Background 5 No Black
Source GDJ
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
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 seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
A free grid paper background pattern for using on web sites.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by TheDigitalArtist
Source Firkin
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Nicely executed tiling for an interesting pattern.
Source Ignasi Àvila Padró
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen