A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
This is a hot one. Small, sharp and unique.
Source GraphicsWall
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Sharp but soft triangles in light shades of gray.
Source Pixeden
Prepared mostly as a raster in Paint.net and vectorised.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
A seamless texture of a rough concrete surface.
Source V. Hartikainen
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Zero CC Mossy stone tileable texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin