A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
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
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
It looks very nice I think.
Source V. Hartikainen
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
You know you love wood patterns, so here’s one more.
Source Richard Tabor
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
This yellow background consists of a pattern of glossy gold buttons arranged in polka dot style on a seamless texture. Here's a pale yellow background pattern. Feel free to use it for your needs!
Source V. Hartikainen