A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.
Source Yamachem
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
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
This is a seamless pattern of regular hexagon which has a honeycomb structure.
Source Yamachem
Remixed from a design seen on Pixabay. The basic tile 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
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
Abstract Tiled Background Extended 8
Source GDJ
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
A version without colours blended together to give a different look.
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin