Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A seamless paper background texture colored in pale yellow. This seamless texture is ideal for those who need a yellow background image for their website. The texture resembles paper.
Source V. Hartikainen
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
This is a remix of "geometrical pattern 01".
Source Yamachem
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
Formed by distorting an image on Pixabay that was uploaded by gustavorezende. To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Dark blue concrete wall with some small dust spots.
Source Atle Mo