As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
From an image on opengameart.org shared by rubberduck.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
A seamless background texture of old cardboard.
Source V. Hartikainen
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
A pattern drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
The image depicts a seamless pattern of pine tree leaves.
Source Yamachem