It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
An aged paper background tile with smeared and pressed text.
Source V. Hartikainen
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
Prismatic Floral Background No Black
Source GDJ
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
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
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Abstract Ellipses Background Grayscale
Source GDJ
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media