And the familiar diamond shape British Registry Office mark, impressed 🙈 British Registry Office mark, ‘Also known as the ‘British Registry Lozenge’ or the ‘British Pattern Registration Diamond’ mark, when present and legible, tells us the date the pattern was registered 😉 To combat plagiarising, the registration process was established in 1842 😎 It makes it unlawful to reproduce that pattern within three years. The exact date of registration is indicated by the numbers and letters in the corners. It was so successful, that it continued to be used throughout the majolica period. Note: The year of pattern registration is not necessarily the year of manufacture but does indicate a ‘circa’ date. 
2. You can see the patterns on new majolica’s outsides from the inside. Also, this is caused from the new pieces being cast. In general, old pieces are made by hand pressing A mould is made by putting clay strips into it. These strips are thicker than normal and smoothed with a sandpaper to get rid of potter fingerprints. The outside patterns on old pieces is rarely visible. Although you may see a few bumps or depressions on old pieces’ insides, there are rarely any identifiable shapes like flower petals, vines and so forth. Slip cast makes the walls of new pieces much thinner. The thin wall covers the exterior pattern, and is visible as the “backside” of the design. 
Ashely grossman realorrepro.com This gives us additional insight. This is an example. While most poorly-made new pieces feature dark colors and dull glazes, others are better. 2 and Figs. 18-22) are made of shiny, smooth glazes in bright colors. Fig. 1 has a glossy, shiny glaze as well as bright colours on some fruit pieces. It also features a 1. It has a background of dark brown with a 2. The base is painted and unglazed. The inside pattern of the exterior is evident (Fig. 14). The most costly piece in our sample, at $149, was this one. However it failed three of the tests. Grace Smith of Kunming in China, on June 8, 2021, amended. 
Experts from homesteady.com The vivid colors of pottery won’t lose their intensity, but they might fade slightly with time. A platter of seafood with finely carved fish, seaweed and a dip cup is still as appealing today as it was back in the 19th century. The pitchers were designed to appear as though they have were made from bamboo stalks. They could also be made with ears of corn or sunflowers. The entire range of majolica was devoted to leaf designs. Plates that looked like begonia leaves were in high demand. Every acquisition became a talking point thanks to its whimsical subjects, which sparked Victorian collectors’ frenzy.