A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Psychedelic Geometric Background No Black
Source GDJ
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
You know you love wood patterns, so here’s one more.
Source Richard Tabor
Inspired by a pattern found in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
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
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless background texture of old cardboard.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen