Antonia Malan sent me the following additional info on
the "Chelsea Sprig" blue sprigged porcelain...
 
Alasdair Brooks
 
 
>Referring to correspondence in early September, I had better put our
>record straight on this stuff.  Having checked with Jane Klose, I
>was slightly off target.  We only find it on bone china here (not
>refined earthenware or porcelain).  And there is a nice article by
>Robin Hildyard in Antique Collecting volume 32 number 4, September
>1997 page 12, on the relationship between Wedgwood's neo-classical
>ceramics and jasper ware and later reversed decoration - i.e.
>sprigging.
 
>Feel free to copy this to Histarch if you think they would be
>interested.