Home-grown company Romscraj has developed one of the world's first portable 3-D printers, called Portabee Go.

When folded, the 2.8kg Portabee Go is only 8cm high and 22cm long and wide - the size of a hardcover book.

From December, it will be available for sale at romscraj.com for US$595 (S$740).

Romscraj co-founder Wee Kiam Peng believes the product can be a useful tool for designersarchitects and engineers when they present plans to clients outside the office.

"Design changes can be made quickly on a computer for the printer to print a new object," said the 38-year-old.

This machine follows the company's first 3-D printer Portabee, which sold more than a thousand units here and overseas for US$495 each.

But Portabee Go almost did not take off.

Earlier this year, Mr Wee approached a government agency for a grant of $250,000 to develop the printer.

"But the officer told me 3-D printers were common and was not supportive. I was disappointed, I knew there was a demand. My partner and I took out (our) savings of $250,000 and invested in the project."

Initial sales inquiries have already come in after the product was presented at two 3-D printing exhibitions in China and Singapore in the last two months.

The six-man team at Romscraj, which has a small production office in Yishun industrial park, is looking at ramping up manufacturing.

"We're hoping to raise $1 million from investors so that we can expand manufacturing to Shenzhen in China," said Mr Wee, a computer engineering graduate from Nanyang Technological University.

One advantage of 3-D printing is that it uses software instead of moulds to make an object. By tweaking the software, objects can be quickly customised.

Initially used by engineers and manufacturers to build quick prototypes, it is now even used to make parts for aircraft engines and medical devices. According to consultancy Wohlers Associates, the 3-D printing market was worth US$2.2 billion worldwide last year, up 29 per cent from 2011.

In Singapore, 3-D printing grabbed headlines earlier this year when another local company, Pirate3D, successfully raised US$1.6 million on crowdfunding site Kickstarter to manufacture its printer called The Buccaneer.

Romscraj - formed from the words "from scratch" - was founded in 2011. It is profitable because of Portabee sales, which have been so good that for two months this year, Mr Wee had to postpone online marketing activities so that the company could catch up with production.

The company's first printer proved popular because it came with detachable parts. When stacked, they could fit into a 14-inch laptop bag.

He was inspired to develop his own device after buying his first 3-D printer for US$1,225 from an American company called MakerBot.

"It came in five parts and I had to assemble the printer myself. As an engineer, I felt we could do a better job," he said.

Even as he prepares the Portabee Go for production, Mr Wee is already developing the company's next innovation - an electronic sensor the size of a 10-cent coin, which can be embedded into an object.

He said: "It has Internet connectivity. It will collect data on prototypes and send the information to designers... It has always been my dream to innovate and create new products that can be sold globally as a Singapore brand."