Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Prismatic Groovy Concentric Background 4
Source GDJ
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Retro Circles Background 8 No Black
Source GDJ
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Retro Circles Background 7 No Black
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ