The East Sussex-based business has picked up several new customers during the period, including the Chartered Institute of Personnel and Development and the charity Cats Protection.
The privately-owned company, which is part of The Pureprint Group, will handle a range of services for the new clients, such as print production, warehousing, fulfilment and point-of-sale work.
According to Will Marsh, client services director of The Glasshouse, the recent strong growth has been achieved through delivering on promises coupled with "sustainable and transparent" costs.
He said: "Cost is of course paramount in the decision-making process for all clients, but we are still in a people business and continuity and expertise of staff is a highly sought-after commodity in today’s difficult trading conditions."
The Glasshouse uses a selection of suppliers for its print services, including Pureprint, as well as companies in Italy and Germany.
"We've delivered on what we said we would and, going forward, our prospects are very strong for 2009," Marsh added.
The Glasshouse seals 3.5m worth of contracts in six months
Print and project management company The Glasshouse has said its prospects for 2009 are "very strong" after securing more than 3.5m in contracts in the past six months.