A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
The image depicts a seamless pattern which was made using stripe-like things including borders.I used OCAL cliparts called "Blue Greek Key With Lines Border" uploaded by "GR8DAN" and "daisy border" uploaded by "johnny_automatic".Thanks.
Source Yamachem
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
Prismatic Snowflakes Pattern No Background
Source GDJ
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zero CC tileable moss or lichen covered stone texture, edited from pixabay. CC0
Source Sojan Janso
Retro Circles Background 4 No Black
Source GDJ
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
A free light orange brown wallpaper with vertical stripes designed for use as a tiled background on websites. An yet another background pattern with vertical stripes.
Source V. Hartikainen
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Retro Circles Background 7 No Black
Source GDJ
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Abstract Tiled Background Extended 11
Source GDJ