Cap and hat designer and producer Mainland Headwear on Thursday posted a small increase in first half net profit to HK$33.3 million from HK32.6m last year on the back of a big jump in sales. The company, whose customers include Warner Brothers, Reebok, Timberland, Fila and Ellesse, said turnover for the six month period soared 31 per cent year-on-year to HK$229m.