Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Just like the black maze, only in light gray. Duh.
Source Peax
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
A gray background pattern with a texture of textile. Suits perfectly for web design.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Have you wondered about how it feels to be buried alive? Here is the pattern for it.
Source Hendrik Lammers
Prismatic Hypnotic Pattern No Background
Source GDJ
Same classic 45-degree pattern, dark version.
Source Luke McDonald
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ