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
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
Neat little photography icon pattern.
Source Hossam Elbialy
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Here's a seamless brown cork board background texture. Feel free to download or reshare if you like.
Source V. Hartikainen
The tile can be had by using shift+alt+i on the selected rectangle in Inkscape
Source Firkin
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim