The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
White circles connecting on a light gray background.
Source Mark Collins
A new one called white wall, not by me this time.
Source Yuji Honzawa
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
One more sharp little tile for you. Subtle circles this time.
Source Blunia
From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
A seamless texture of black leather. I think it will look best when used in headers, footers or sidebars.
Source V. Hartikainen
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
A background pattern with green vertical stripes. A new striped background pattern. This time a green one.
Source V. Hartikainen
I’m not going to use the word Retina for all the new patterns, but it just felt right for this one. Huge wood pattern for ya’ll.
Source Atle Mo
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Polka Dots Mark II 2 No Background
Source GDJ