Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Lovely pattern with splattered vintage speckles.
Source David Pomfret
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
The image depicts a seamless pattern of the design which includes a stylized lotus and a stylized crane.I referred to the original image in a book which is into public domain.
Source Yamachem
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Abstract Background Design No Black
Source GDJ
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
A bit strange this one, but nice at the same time.
Source Diogo Silva
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin