The base gradient edited so now more details are rendered.
Source Lazur URH
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
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 design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
This was formed by distorting an image of a background on Pixabay.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L