Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
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
Prismatic Groovy Concentric Background 2
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 5
Source GDJ
A pale olive green background with a seamless texture.
Source V. Hartikainen
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Abstract Tiled Background Extended 11
Source GDJ
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel