A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
Black & white version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
One week and it's Easter already. Thought I would revisit the decorated egg contest at inkscape community: http://forum.inkscapecommunity.com/index.php?topic=118.0
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
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Prismatic Hexagonalist Pattern No Background
Source GDJ
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo