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
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
A version without colours blended together to give a different look.
Source Firkin
You may use it as is, or modify it as you like.
Source V. Hartikainen
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless textured paper for backgrounds. Colored in pale orange hues.
Source V. Hartikainen
A web texture of brown canvas. Will look great, when used in dark web designs.
Source V. Hartikainen
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Colour version of the original seamless pattern.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran