The lack of investment worries the Qualifications and Curriculum Authority, which says that two-thirds of design and technology teachers believe it is limiting the range of work their pupils can undertake.
"The Design and Technology Association's 2003 survey also showed that 90 per cent of pupils provide their own materials for lessons," Louise Davies, one of the QCA's design and technology specialists, said last week. "We don't ask children to do this in any other subject.
"We also need more investment in design and technology departments themselves. On average they were last refurbished 10 years ago."
Ms Davies acknowledged that the Office for Standards in Education recently described design and technology as the "most improved subject".
It was also extremely popular with pupils and more than 200,000 were now taking GCSEs in the subject. But as design and technology will become optional in September, some of the progress that had been made since the introduction of the national curriculum could be under threat, said Ms Davies, who was speaking at an Audi Design Foundation dinner in London.
"We can celebrate what we've achieved in design and technology because we are emulated by countries all over the world," she said. "But we do need to address some significant issues, apart from funding.
"If the subject is to continue to be taken by large numbers of pupils we will need more specialist teachers - 67 per cent of schools say they have trouble filling vacancies."
Ms Davies said that the continuing pressure for improved exam results could cause teachers to "heavily structure" their pupils' learning and reduce the scope for innovation and creativity. She also said the education service had to recognise that design and technology teachers would only remain passionate about their subject if they were not overburdened.
Many secondary schools did not have enough technician support, even though teachers could be overseeing between 160 and 200 projects. "It isn't a teacher's job to wash tea towels or sort out tools in preparation for a class," she said. "Many of them need more help."