The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
The original has been presented as black on transparent and stored in the pattern definitions. To retrieve the unit tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Number five from the same submitter, makes my job easy.
Source Dima Shiper
A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
Here's a seamless brown cork board background texture. Feel free to download or reshare if you like.
Source V. Hartikainen
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle