A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
This is a seamless pattern of a woody texture.The original image is here:https://pixabay.com/ja/users/ClassicallyPrinted-1302233/
Source Yamachem
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Abstract Tiled Background Extended 6
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Prismatic Groovy Concentric Background No Black
Source GDJ
Subtle scratches on a light gray background.
Source Andrey Ovcharov
8 by 8 pixels, and just what the title says.
Source pixilated
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Zero CC tileable hard cover red book, scanned and made by me. CC0
Source Sojan Janso
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.
Source Firkin