A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
Source V. Hartikainen
A new one called white wall, not by me this time.
Source Yuji Honzawa
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
Subtle scratches on a light gray background.
Source Andrey Ovcharov
Kaleidoscope Prismatic Abstract No Background
Source GDJ
The classic notebook paper with horizontal stripes.
Source Are Sundnes
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Prismatic Groovy Concentric Background 5 No Black
Source GDJ