Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
You guessed it – looks a bit like cloth.
Source Peax Webdesign
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
Prismatic Polka Dots Mark II No Background
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
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
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