Here's a dark background pattern that contains a steel grid pattern as a texture. Use it as a website background or for other purposes. It's free!
Source V. Hartikainen
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
The image depicts polka dot seamless pattern.
Source Yamachem
Used a cherry by doctormo to make this seamless pattern
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Light and tiny, just the way you like it.
Source Rohit Arun Rao
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Colored maple leaves scattered on a surface. This is tileable, so it can be used as a background or wallpaper.
Source Eady
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski