Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
Prismatic Geometric Pattern Background
Source GDJ
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective