From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.
Source V. Hartikainen
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
A blue gray fabric-like texture for websites. An yet another fabric-like texture. It has subtle vertical and diagonal stripes to it.
Source V. Hartikainen
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
You know you love wood patterns, so here’s one more.
Source Richard Tabor
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
This was formed by distorting an image of a background on Pixabay.
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Prismatic Hexagonalism Pattern No Background
Source GDJ
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin