Schools, particularly primaries, are becoming increasingly reliant on parents to raise funds for essential equipment.
And primary heads have warned that, as Scottish council budgets face a potential "double whammy" in funding cuts next year, this trend is likely to get worse.
Irene Matier, president of the union for primary heads, said headteachers were predicting they would soon have to ask children to bring their own paper, pens and pencils to school because their budgets were becoming so tight.
Members of the Association of Headteachers and Deputes in Scotland were reporting cuts in primary schools ranging from 10 to 50 per cent, she said.
A survey of parent councils and parent teacher associations, published today, shows that one primary parent body expected to have to raise pound;19,000 in a year; in one large urban secondary, the figure was pound;10,000.
Eileen Prior, executive director of the Scottish Parent Teacher Council (SPTC), which carried out the survey, said that play, IT and sports equipment were the major areas of spending for parent fundraisers.
"You would be forgiven for thinking these are more traditional areas of core funding by local authorities," she said.
The SPTC's research demonstrated just how dependent schools now were on funds raised by parents. Primary schools tended to have much closer links with parent bodies and could therefore rely on more parent-based funding, but secondaries were likely to struggle financially because parents were less engaged with them, she predicted.
In primary schools, the provision of IT equipment, including interactive whiteboards and items such as printer cartridges and replacement printers, is often down to parents' fundraising activities, said Mrs Matier.
"There was a time when funds raised by parents would have been for extras for children, like school trips. But there has been a very definite requirement to change that and ask parents to raise money for core materials," she said.
Many primary schools now relied on parents to raise money to buy play equipment, added Mrs Matier. "Active outdoor learning is a very large part of what we do now," she said. "Having equipment in the playground is essential for us."
Other schools have had to ask parents to fundraise for replacement textbooks and library books.
The SPTC survey received responses from 311 schools - around one in 10 schools in Scotland - and its findings will be sent to the inquiry into the funding of education services being carried out by the Scottish Parliament's education committee.
Concerns about education funding were heightened this week by the announcement from John Swinney, the Finance Secretary, that he plans to delay Holyrood's share of the UK Government's pound;6 billion cuts in public spending until next year.
He admitted that this policy would create a "double whammy" of cuts in 2011-12, kicking in after the Holyrood elections.