This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
From a drawing in 'Danmarks Riges Historie af J. Steenstrup, Kr. Erslev, A. Heise, V. Mollerup, J. A. Fridericia, E. Holm, A. D. Jørgensen', 1897.
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Retro Circles Background 5 No Black
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
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
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
An abstract pale yellow paper-like background with stains colored in yellow and green.
Source V. Hartikainen
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso