A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
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
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
This is a grid, only it’s noisy. You know. Reminds you of those printed grids you draw on.
Source Vectorpile
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Prismatic Geometric Pattern Background
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The name is totally random, but hey, it sounds good.
Source Atle Mo
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from an image that was uploaded to Pixabay by CatherineClennan
Source Firkin
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
Seamless pattern formed from a tile that can be extracted 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
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin