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
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Kaleidoscope Prismatic Abstract No Background
Source GDJ
A frame using leaves from an image that was uploaded to Pixabay by mayapujiati
Source Firkin
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
Prismatic Groovy Concentric Background No Black
Source GDJ
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
Kaleidoscope Prismatic Abstract No Background
Source GDJ
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen