Toyama Gakki AULOS Symphony Tenor Recorder Baroque Style with Hard Case 511B(E) Black, Ivory Brand: Toyama Gakki Instrument Key: C Sharp, C Material: Plastic There may be faint lines that occur during the manufacturing process of plastic products, but these do not affect the product at all. There are thin vertical lines in the finger holes, but is this a problem? The flow lines of the resin that are created during molding are called weld lines, and they occur vertically in relation to the finger holes. This is a common occurrence in recorders made of plastic and does not indicate a problem with quality.