Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using 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
Prismatic Abstract Background Design No Black
Source GDJ
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
A heavy hitter at 400x400px, but lovely still.
Source Breezi
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Continuing the geometric trend, here is one more.
Source Mike Warner
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Have you wondered about how it feels to be buried alive? Here is the pattern for it.
Source Hendrik Lammers
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo