A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Fix side and a seamless pattern formed from circles.
Source SliverKnight
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
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
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin