Weft count variation:
If the weft yarn count varies for a short length say 4 - 5 metres, the weft bars appear on the fabric surface. It can be repaired by replacing the defected pick by fresh yarn.
If the weft count varies for a long length, it results in form of low and high thickness bands in the fabric. If there is very low count variation for long length, the bands do not appear clearly in the grey fabric. When this fabric is dyed , the light and dark colour bands appear prominently on the fabric surface.
If the weft yarn count variation occurs for long weft yarn length, the GSM of the fabric also varies.
Individual weft bar can be repaired but GSM variation, thick and thin bands are not repairable. These irregularities are unacceptable. The whole fabric gets rejected due to these kinds of defects.