Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
Sort of reminds me of those old house wallpapers.
Source Tish
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless web background with texture of aged grid paper.
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
Prismatic Abstract Geometric Background 3
Source GDJ
A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
A comeback for you: the popular Escheresque, now in black.
Source Patten
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ