A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
This is a hot one. Small, sharp and unique.
Source GraphicsWall
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
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
The classic notebook paper with horizontal stripes.
Source Are Sundnes
This is a grid, only it’s noisy. You know. Reminds you of those printed grids you draw on.
Source Vectorpile
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
A seamless canvas texture for using as background on websites. Colored in pale tones of brown.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free seamless background pattern for use on websites.
Source V. Hartikainen
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee