The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
Prismatic Abstract Line Art Pattern Background
Source GDJ
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Prismatic Triangular Background Design Mark II 5
Source GDJ
A gray background pattern with a texture of textile. Suits perfectly for web design.
Source V. Hartikainen
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
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 formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin