Every early 19th-century reproduction line needs a print with a fancy machine ground.
For my Lately Arrived From London collection for Moda I had a rather large piece of fabric with a floral trail figure atop a detailed "fancy machine ground." The document print above is the larger piece, the reproduction is the smaller square. It may date to about 1820-1840.
In the englargement you can see the finely detailed dots behind the florals. They not only add a background, they form part of the floral figures. These backgrounds were not engraved on the roller by hand; they were applied in a machining process.
Above: the tan reproduction in the top left and the larger brown document print for the Meryfield print from my Hartfield collection, an early-19th-century line I did a few years ago. The green leaves in the original were probably done with a wood block, the brown ground printed with a roller. Notice the streak in the fancy machine ground, indicating it crimped in the roller.
Once printers figured out how to apply detailed machining to copper rollers the designers came up with many outrageous combinations as in the print from an old quilt above. The insect-like figure and the striped machined ground have very little in common. And then there are those green sticks.... People loved the variety and the layers of detail.
Designers and customers welcomed the new look about 1810 because older wood-block printing limited the types of backgrounds. One typical wood block ground was a solid color hand applied around the figures with a wood block, as in the chintz above. The technology wasn't perfect and printers often left haloes of white between the figure and ground---the registration was off.
For more detail the block printer could add a patterned ground behind the figure, in this case a regularly spaced dot, probably applied with a wood block fitted with pins in a regular pattern. In England these dotted grounds were called Stormont grounds, in France picotage.
But the fancy machine grounds were ---well much fancier---than the old Stormont grounds. Once the roller printed grounds were possible the designers and the printers showed their skills in many combinations of figure and ground. The detail is impressive, the registration is perfect---the only flaw (if one were being picky) is that the design combinations were sometimes strange.
So if you are looking for an authentic 1810-1840 look buy prints with detailed grounds---fancy machine grounds. You wouldn't see them any earlier than 1800 because the technology wasn't there yet. And they fell out of favor about 1840 as new styles developed.
Above is the Little Molly print in the muslin colorway that shows the fancy machine ground off the best.
In the tea colorway the shading dominates the florals, creating a rainbow look.
In the plum colorway the ground is more subtle and the figure stands out.