A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
Classic vertical lines, in all its subtlety.
Source Cody L
More in the paper realm, this time with fibers.
Source Jorge Fuentes
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
You know you love wood patterns, so here’s one more.
Source Richard Tabor
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
The image a seamless pattern of a wire-mesh fence.I want you to use this pattern as a lower layer.
Source Yamachem
Prismatic Geometric Pattern Background No Black
Source GDJ
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
Zero CC Mossy stone tileable texture, photographed and made by me. CC0
Source Sojan Janso
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett