It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
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
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
This one is amazing, truly original. Go use it!
Source Viahorizon
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L
Background formed from the original with an emboss effect
Source GDJ
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
U.S.-based National Fire Protection Association standard fire diamond for flagging risks posed by hazardous materials. The red diamond has a number 0-4 depending on flammability. The blue diamond has a number 0-4 depending on health hazard. The yellow has a number 0-4 depending on reactivity. the white square has a special notice, e.g OX for oxidizer.
Source Firkin
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
More in the paper realm, this time with fibers.
Source Jorge Fuentes
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem