The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
White handmade paper pattern with small bumps.
Source Marquis
Embossed lines and squares with subtle highlights.
Source Alex Parker
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Sharp pixel pattern, just like the good old days.
Source Paridhi
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
Prismatic Triangular Background Design Mark II 5
Source GDJ
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Here's a repeatable texture that resembles a light green concrete wall or something similar.
Source V. Hartikainen
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin