Embossed lines and squares with subtle highlights.
Source Alex Parker
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
Colorful Floral Background No Black
Source GDJ
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Geometric triangles seem to be quite hot these days.
Source Pixeden
Prismatic Geometric Pattern Background 2
Source GDJ
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
The original enhanced with one of Inkscapes's filters.
Source Firkin
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868.
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski