This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Prismatic Hexagonalist Pattern No Background
Source GDJ
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
Prismatic Groovy Concentric Background No Black
Source GDJ
Seamless pattern formed from a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß