I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Classic 45-degree pattern, light version.
Source Luke McDonald
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Nicely executed tiling for an interesting pattern.
Source Ignasi Àvila Padró
Dark blue concrete wall with some small dust spots.
Source Atle Mo