Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
Sort of reminds me of those old house wallpapers.
Source Tish
The image depicts a tiled seamless pattern.The tile represents four leaves aligned every 90 ° , which may look like a bird or a dragon .The original leaf design is from a Japanese old book.
Source Yamachem
An alternative colour scheme to the original seamless pattern.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
Sharp but soft triangles in light shades of gray.
Source Pixeden
A seamlessly tileable pink background texture.
Source V. Hartikainen
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
An abstract Background pattern of purple twisty patterns.
Source TikiGiki
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
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
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem