Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
Here's a seamless brown cork board background texture. Feel free to download or reshare if you like.
Source V. Hartikainen
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Prismatic Abstract Geometric Background 4
Source GDJ
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
From a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
You may use it as is, or modify it as you like.
Source V. Hartikainen
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin