Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Element of beach pattern with background.
Source Rones
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
From drawing in 'Musings in Maoriland', Thomas Bracken, 1890.
Source Firkin
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
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
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Abstract Tiled Background Extended 10
Source GDJ
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin