This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen
From a drawing in 'La Principauté de Liège et les Pays-Bas au XVIe siècle', Société des Bibliophiles Liégeois ,1887.
Source Firkin
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
A version without colours blended together to give a different look.
Source Firkin
Prismatic Hypnotic Pattern No Background
Source GDJ
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Prismatic Curved Diamond Pattern No Background
Source GDJ
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman