Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.
Source Yamachem
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
Prismatic Geometric Pattern Background 2
Source GDJ
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
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