Patty Wilson, who lives down the street from the county office building in Rockville, doesn't fit the stereotype of the Montgomery County suburban housewife. Twenty-years-old and with her husband in jail, she is struggling to stretch her money far enough to cover the basics - food and housing and clothes.

Sometimes she finds that she can't. There isn't any more.

She washes her 6-month-old daughter's diapers by hand, soaking and resoaking them, trying to get them clean enough to prevent diaper rash. She can't afford a washing machine, and she doesn't have money for the laundromat. This month, she said, she is not sure she will have enough money to buy food stamps for herself and her daughter.

Wilson is one of about 12,000 Montgomery County residents who use food stamps. The federal assistance program serves only about 36 per cent of the Montgomery County residents estimated eligible for its services and about 47 per cent of those in Prince George's County, according to 1976 statistics.

The figures look low until they are set against the national average. Across the country only about 38 per cent of those whose incomes are low enough to qualify for food stamps used them in 1975. The U.S. Department of Agriculture now estimates that approximately 50 per cent of those eligible to receive them use the stamps in a given month.

The difficulties that Patty Wilson and other Montgomery County residents face in trying to take advantage of the program point up its weaknesses and why some people who could use the program don't, according to anti-poverty advocates and some officials.

One of those difficulties, according to people who use the program, is scraping together the money to pay for the stamps. Most users pay a percentage of their income to participate. For instance, a family of four might buy $162 worth of stamps a month for $71 - a 56 per cent discount.

It's not a lot of money, said several officials who work in the food stamp program. But users said it looked different from their perspectives.

Wilson is on public assistance and receives $197 in income monthly, she said. Of that $110 goes for rent and the rest for utilities, food and clothing for Eulanda, a bright-eyed, happy baby.

Last month Wilson expected a gas bill of about $66 because she got behind in January. There was a gas leak in her apartment and she held off paying while she worked out with the gas company whether she would be charged for the whole amount.

They deducted $6, she said.

She is supposed to pay $18 for food stamps, more money than she expects to have left over when she pays her bills. She has to pay the gas bill or face the prospect of being cut off, she said.

For her, $18 looms as a large amount of money, she said.

She could buy less than her allotment of food stamps, but "I need all of them," she said. "The baby is on table food," she said, tilting a bottle into the baby's mouth.

Other recipients said they had found themselves in the same predicament as Wilson from time to time, as unexpected expenses arose. A survey by the Montgomery County department of social services in May, 1975, also found not having enough money a major reason for people not using the program. Out of 101 clients who were certified for food stamps but did not use them, the survey found that 47 didn't because they felt they couldn't afford them.

"It's too bad we can't just give it to them instead of their having to put out the money," said C.D. Lester, associate director of the social services department. But the choice isn't up to the county, the requirement is part of federal law.

So are the procedures for certifying recipients as eligible for the program, procedures which present a major obstacle themselves, according to people who work with food stamp users.

"The food stamp application is four pages long and requires double entry bookkeeping," said Anne Elward, who works for the Montgomery County extension service.

"These people aren't able to cope with that. For every statement of income from every source, you have to have written proof. Poor people as a class aren't organized," said Elward. "If they were organized, they'd be out getting jobs like you and me," she said.

The application, four sheets of small type set on a green background, requires the applicant to code his employement status and citizenship, plow through about 100 items and answer questions such as listing for working members of the family sources of income and deductions for Social Security, taxes, union dues and retirement.

"We get people in the office all the time who say, 'I can't get through the paper. I can't get through the forms,'" said Sherry Mitchell, a food stamp recipient who works with an organization of food stamp clients to help uncomplicate the system.

Those whom incomes fluctuate month to month - primarily the working poor who may have jobs as construction workers or domestics where their income is variable - have to be recertified with some frequency. Although there are systems that allow applicants to send a proxy or to mail in information for certification, many would-be food stamp users are unaware of them, said activists who work with the poor.

In both Montgomery and Prince George's counties, church groups organized into the Community Ministry help people around the stumbling blocks. The group in Prince George's County provides transportation for people to get to the certification offices, makes appointments for certification for applicants, and works closely with the department of social services. Both county groups also provide emergency cash grants to families who can't scrape together the money for their stamps.

The social services departments in both counties have tried to make it easier for people to apply and buy the stamps, their officials said. In Prince George's County stamps are sold at seven branch banks. Montgomery County has two offices where applicants can be certified and buy stamps and six other outreach centers open once a month.

"The real hang-ups are constant recertification and amassing enough cash to buy a month's worth of stamps," said Esther Delaplane, a Montgomery County pupil personnel worker who has been active on a couty task force dealing with hunger and nutrition.

There is another, more intangible reason why people don't use the Mary Goodwin. "It's hard to be poor in a rich county. It's painful for people."