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
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Psychedelic Geometric Background No Black
Source GDJ
A free seamless background with pink spots.
Source V. Hartikainen
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
Prismatic Abstract Line Art Pattern Background
Source GDJ
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
Fix side and a seamless pattern formed from circles.
Source SliverKnight
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
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
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin