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
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Prismatic Groovy Concentric Background
Source GDJ
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
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
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Prismatic Abstract Line Art Pattern Background
Source GDJ
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin