A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle 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
To get the repeating unit, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
There are many carbon patterns, but this one is tiny.
Source Designova
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Seamless SVG vector and JPG backgrounds with faded diagonal stripes. The colors are editable.
Source V. Hartikainen
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A simple bump filter made upon request at irc #inkscape at freenode. Made a screen capture of the making here: https://youtu.be/TGAWYKVLxQw
Source Lazur URH
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
White circles connecting on a light gray background.
Source Mark Collins
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen