I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This one needs to be used in small areas; you can see it repeat.
Source Luca
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A version without colours blended together to give a different look.
Source Firkin
Seamless Prismatic Geometric Pattern With Background
Source GDJ
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH