An attempt for cleaning up the original image in a few steps.
Source Lazur URH
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
The original enhanced with one of Inkscapes's filters.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
The tile can be had by selecting the rectangle in Inkscape and using shift+alt+i. Remixed from a drawing in 'Flowers of Song', Frederick Weatherly, 1895.
Source Firkin
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
Alternative colour scheme for the original floral pattern.
Source Firkin
Black And White Floral Pattern Background from PDP.
Source GDJ
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio