The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Abstract Ellipses Background Grayscale
Source GDJ
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
White little knobs, coming in at 10x10px. Sweet!
Source Amos
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
A seamless background of warped stripes on paper.
Source V. Hartikainen
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
Sort of reminds me of those old house wallpapers.
Source Tish
Lovely pattern with splattered vintage speckles.
Source David Pomfret
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
A bit strange this one, but nice at the same time.
Source Diogo Silva
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
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
Can’t believe we don’t have this in the collection already! Slick woven pattern with crisp details.
Source Max Rudberg
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin