Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
From a drawing in 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Green Web Background, Seamless tile.
Source V. Hartikainen
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Geometric triangles seem to be quite hot these days.
Source Pixeden
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
The rectangular tile 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 based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Prismatic Abstract Background Design
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Abstract Line Art Pattern Background
Source GDJ
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
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
Inspired by a design found in 'Konstantinápolyi emlékeim', Miklos Chriszto, 1893.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin