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 slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.
Source V. Hartikainen
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
The classic notebook paper with horizontal stripes.
Source Are Sundnes
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
"Beige Stone", Tileable Texture.
Source V. Hartikainen
This texture looks like old leather. It should look great as a background on web pages.
Source V. Hartikainen