This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Prismatic Abstract Geometric Background 5
Source GDJ
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
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Prismatic Groovy Concentric Background 4
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
A seamless pattern of leopard skin. It should look nice as a background element on web pages.
Source V. Hartikainen
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin