**1. Introduction**

Technological aspects of ceramic production in the past were not only affected by the mastery and innovation of the local craftsmen but the transfer of technology coming out of cultural interactions between societies. This is well-reflected in the choice of the raw materials used and the firing conditions as well as in decorative processes such as enameling. Regarding porcelain production in the Far East, a long-distance technological transfer is known to have been conducted by Portuguese Jesuit missions in Japan at the beginning of the 17th century [1–3]. Historical records of the Chinese court and Jesuit mission [4–8] also both demonstrated the importation of European enamels and ingredients as well as

the venue of European craftsmen who had expertise in enameling techniques at the Qing court at the end of 17th century. These enamels are called "*falangcai*" (琅彩 from *falang*, a homonym of the "French" character in Chinese) and/or "*yangcai*", (洋彩 "foreign colors") [9], which are deposited generally over the glaze, the latter being fired beforehand with the porcelain body. Although porcelain production was first achieved in China historically, the craft of enameling is generally suggested to have benefited with Western contacts as early as the 14th century via the Silk Road [10–15].

Scientific analyses of various Chinese [10–15] and European [11,16–18] enameled artifacts have previously confirmed the use of a blue enamel precursor (usually called "smalt") based on European cobalt ores and Naples yellow lead pyrochlore pigments typical of European recipes in enameled metalware and porcelains produced during the Qing dynasty. Furthermore, the use of the European "Cassius purple" method to prepare pink to purple porcelain enamels (the so-called *Famille rose*) with colloidal gold had been well-established for decades [19]. Due to the rareness of artifacts produced at the Beijing Imperial Palace Workshop (*falangzuo* (珐琅作), enamel workshop) and, consequently, the lack of fragments of such artifacts, most of the studies have been conducted with noninvasive techniques, in particular on-site with Raman and X-ray fluorescence (XRF) mobile instruments [10–14,16–18,20], which are well-suited for the in situ study of outstanding objects in their secure locations [20–24]. UTF8gbsn We present here an on-site noninvasive Raman study of Chinese porcelain masterpieces assigned to have been produced at the beginning of the 18th century (Yongzheng (1723–1735) and beginning of Qianlong (1735–1796) reigns) belonging to the collections of the Louvre Museum and Chinese Museum at Fontainebleau Castle in France. One artifact has also been analyzed with a mobile XRF microspectrometer. A comparative approach was carried out with the first Raman study focused on porcelains produced at the end of the Kangxi reign (1661–1722) and the beginning of the Yongzheng reign [12] and with painted enameled metalware of the same collections [14] as well as other types of European enameled artifacts [11,16–18].
