However, the porcelain collector should note that early Coal Brook Dale marks are extremely rare and very collectible.The early Coalport porcelain wares are mostly unmarked.
c1810 to 1825, rare examples of Coalport porcelain is marked in underglaze blue, ‘Coalbrookdale’, ‘CD’ or ‘C. c1815 to 1825, some Coalport plates and dishes include impressed numerals. c1845 to 1855, Coalport produced many Sevres & Chelsea porcelain imitations that can often include copies of the original Sevres or Chelsea marks.
During the 1830s the factory initiated the practice of applying a light transfer printed blue outline, to guide the painters.
This preserved some of the freedom of hand-painted decoration, while it enabled Rose to keep up the pace of production.
By 1796, when John Rose, Blakeway & Co moved from Jackfield to their new factory at Coalport they were producing a good quality hard-paste, fashioned in many instances after those of Flight & Barr of Worcester.
The characteristics of his pioneer's effords were a greyish porcelain of poor translucency, flawed with black specks with dull grainy glaze, but stronger and less expensive than the soft porcelain of 1750-60.