This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Green Web Background, Seamless tile.
Source V. Hartikainen
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
A seamless pattern formed from miutopia mug remixes on a tablecloth.
Source Firkin
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Number five from the same submitter, makes my job easy.
Source Dima Shiper
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
The name Paisley reminds me of an old British servant. That’s just me.
Source Swetha
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin