Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless texture of worn out "cardboard".
Source V. Hartikainen
A background pattern with green vertical stripes. A new striped background pattern. This time a green one.
Source V. Hartikainen
A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.
Source Firkin
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
Remixed from a drawing in 'Canadian forest industries July-December', 1915
Source Firkin
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Sharp pixel pattern, just like the good old days.
Source Paridhi
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
One more sharp little tile for you. Subtle circles this time.
Source Blunia
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
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
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
White little knobs, coming in at 10x10px. Sweet!
Source Amos
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin