Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
The name is totally random, but hey, it sounds good.
Source Atle Mo
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. Version with black background.
Source Firkin
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
An alternative colour scheme for the original background.
Source Firkin
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
A lot of people like the icon patterns, so here’s one for your restaurant blog.
Source Andrijana Jarnjak
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
Looks like an old rug or a computer chip.
Source Patutin Sergey
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
Inspired by a drawing in 'Poems', James Smith, 1881.
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Prismatic Curved Diamond Pattern No Background
Source GDJ