Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
This could be a hippy vintage wallpaper.
Source Tileable Patterns
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
A repeating background with seamless texture of stone. There haven't been any stone-like backgrounds for a while, so I have decided to create one more. The rest can be found in the appropriate category.
Source V. Hartikainen
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
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
A seamless background colored in pale orange. It has a paper like texture with diagonal grid pattern.
Source V. Hartikainen
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin