A separate form of the spiral pattern is that used for borders, otherwise called the wave or maeander, which merged into the guilloche. Although the chain of coils on the scarab borders in the XIIth dynasty may be regarded as a wave border, yet no example is known of this border on other objects until the XVIIIth dynasty. At that time it appears as often on foreign objects as on Egyptian, and the only instance of the guilloche is on foreign dress. Hence this development of the spiral idea may well be due more to the Aegean civilisation than to that of Egypt. This will agree with the occurrence of the guilloche on black pottery from Kahun, which class, wherever it can be dated, is found to belong to the XIIth-XIIIth dynasty. The metal vases shown on the monuments of the XVIIIth-XXth dynasties are mostly foreign tributes, and on them the wave border is common, merging into a twisted rope border which is also found—though rarely—on scarabs of the Middle Kingdom.