A comeback for you: the popular Escheresque, now in black.
Source Patten
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
Colorful Floral Background 3 No Black
Source GDJ
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Prismatic Groovy Concentric Background 3
Source GDJ
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
A seamless pattern of "sewn stripes" colored in light gray.
Source V. Hartikainen
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Inspired by a pattern found in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
Prismatic Abstract Line Art Pattern Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin