A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
The image depicts a pattern of regular hexagon.As I made to use it for myself,I want to others to use it.Speaking about the ratio of the image, height : width = 2 : √3(1.732...)Ridiculous to say,I realized later that this image is not honey comb pattern.I have to slide the second row.
Source Yamachem
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks. https://cloaks.deviantart.com
Source Atle Mo
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Prismatic Geometric Pattern Background 2
Source GDJ
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
Prismatic Snowflakes Pattern No Background
Source GDJ
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Sharp pixel pattern, just like the good old days.
Source Paridhi
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Basket Fibers, Basket Texture, Braid Background style CC0 texture.
Source 1A-Photoshop
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A light brushed aluminum pattern for your pleasure.
Source Tim Ward