From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Here's a tile-able wood background image for use in web design.
Source V. Hartikainen
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
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
Prismatic Groovy Concentric Background 5
Source GDJ
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn