This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
I’m not going to lie – if you submit something with the words Norwegian and Rose in it, it’s likely I’ll publish it.
Source Fredrik Scheide
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Abstract Tiled Background Extended 8
Source GDJ
From an image on opengameart.org shared by rubberduck.
Source Firkin
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Hypnotic Pattern No Background
Source GDJ
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Psychedelic Geometric Background No Black
Source GDJ
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin