From a drawing in 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem
Retro Circles Background 7 No Black
Source GDJ
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
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
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc