ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
Light and tiny, just the way you like it.
Source Rohit Arun Rao
Inspired by a drawing in 'Poems', James Smith, 1881.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
This one needs to be used in small areas; you can see it repeat.
Source Luca
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
The image is a design of blue glass.How about using it as background image?
Source Yamachem
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
This is sort of fresh, but still feels a bit old school.
Source Martuchox
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen