(Sharecast News) - Printing outfit Grafenia saw first-half losses widen as its trade print business battled against headwinds and increased investments into the group's US expansion offset much of its revenue growth.Pre-tax losses widened 193% in the six months to 30 September to £1.44m, despite a 23% rise in revenues to £8.31m as a result of increasing costs, eroding margins and a tougher backdrop for its trade print business."Like the majority of printers, we've suffered from increased pricing on paper, our biggest raw material purchase," the company said.Grafenia swung to an EBITDA loss of £310,000 from the profit of £430,000 recorded a year earlier and losses per share widened to 1.75p from the 0.86p recorded in the prior period.Net debt was cut 58% to £1.06m.Grafenia, which plans to launch its Nettl retail store format across America in 2019, said the expansion would be a headwind to reported operating costs in the coming half, but stated the opportunity was too "significant" to ignore.As of 0935 GMT, Grafenia shares had inched forward 0.48% to 10.55p.