Ornela Seed Bead #11 Transparent Rainbow Green. The Preciosa Company is renowned for the quality of its Czech seed beads. The knowledge and long experience of its glass makers, combined with its unique modern technology, result in superior production of a wide range of colours and sizes. Many of the worldÂ???Ñs most highly esteemed jewellery and loom work pieces have been created by using Preciosa Czech seed beads exclusively. Size and shape may vary slightly and colour may vary from dye lot to dye lot. Hanks consist of 12 to 14 strands, approximately 4,000 beads.