Thanks, the link to Rogers term did not work on my end.This kind of ornamental design and style comes from the Renaissance period. In Italian Renaissance style leaves are often somewhat thin more pointed and a bit "dry". The German Renaissance style has leaves that generally are more beefy; seem to be full of sap, strongly growing, round shaped. One artist that has engraved about 100 small copper plates for printing such ornaments was Heinrich Aldegrever. https://en.wikipedia.org/wiki/Heinrich_Aldegrever
Although not as famous as Dürer, his work is of high artistic quality. He is counted in the group of the "Little masters" which seems underestimating his art. But compared to Dürer, other artist´s work mostly look weaker.
I think that the quality of his engravings is not consistent, but there are some real gems to find. I suggest to go to http://lj.rossia.org/users/marinni/416035.html and download all of these nice high resolution pictures.
The best panel for a thorough study is the long vertical panel with the two putti named AN00125860_001_l.jpg It shows the basic leaf in a wide variety of variants of shape and use. Basically Aldegrever composes this panel using just a few variations. Maybe you do not like them, but these are well worth to study!! Shading is simple, but effective and cannot be employed this way on a fine gun. Maybe it is strange to find all the other motifs in these panels, Insects humans, fantasy figures etc. But these are element that could be employed enriching all too boring layouts. Actually one could build a layout around these! Godd are also AN00085096_001_l.jpg and AN00125537_001_l.jpg. Not to speak of the more complicated panels. Also study them for the layout and look where the “plant†(main stem of the ornament) grows from.
P.S. "Blackleaf" is a stange term to my ears.... I think this word was used first in the former Eastern Germany, Suhl. In books one also can read "Schwarzlaub", -so far the translation is correct. Roger C. Bleile explained it correct in his glossary. http://www.engravingglossary.com/Hand Engraving Glossary A.htm Arabesque is a fully wrong name for this style. Again Roger states it correct.
All the best,
Martin
Sam, you are right.
And I better should not act like a teacher, I am on holiday