Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
Prismatic Geometric Pattern Background
Source GDJ
A seamless canvas texture for using as background on websites. Colored in pale tones of brown.
Source V. Hartikainen
The classic notebook paper with horizontal stripes.
Source Are Sundnes
From a drawing in 'Danmarks Riges Historie af J. Steenstrup, Kr. Erslev, A. Heise, V. Mollerup, J. A. Fridericia, E. Holm, A. D. Jørgensen', 1897.
Source Firkin
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
This one is amazing, truly original. Go use it!
Source Viahorizon
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Prismatic Polyskelion Pattern No Background
Source GDJ
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski