Technically, Balts and Slaves have both come from proto-baltic-slavic people (that came from proto-indo-europeans, and much older then VI century, existed not for long), from wich proto-balts and proto-slavs came. Accordingly, balts and slavs came from them, so while having distant common heritage, they - balts and slavs, weren't one lingvistic unity. As for slavic boarders, I can tell only about their western boarder, even the first branch - proto-balts-slavs, were never at baltic sea, and later proto-slavs and slavs were allways to the east and south from balts. i could tell even more that proto-balts lived from baltic sea to somewhere around moscow (though thats something i personally am sceptical about).. Sorry for OT! As for ornament - yeap, looks quite indo-eiropeaniash to me - lithuanian, latvian, belarussian, etc