The following repeating website background is colored in a blue gray color and resembles a concrete wall or something similar to it.
Source V. Hartikainen
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Embossed lines and squares with subtle highlights.
Source Alex Parker
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
A seamless pattern formed from background pattern 102
Source Firkin