Intended to give teachers a structure for reflecting on their classroom practice and professional development - as well as keeping their details together - the portfolio has been applauded by teachers looking for promotion.
Ms Huntley, who after seven years at the school is looking for a job as a key stage 2 co-ordinator, usually reads through her portfolio before going for interviews. Its contents, she says, help her prepare for possible questions about what she has achieved in her present role as a special needs and art co-ordinator, and what she is doing to tackle areas of weakness.
But what individuals get out of the portfolio depends on how much effort they are prepared to put into it. "I have found it very useful when I've applied for jobs, but some long-established members of staff wouldn't use it as much, " says Ms Huntley. She has kept a record of the courses she attended even before the portfolio was introduced.
"I think it's more useful if you've been using it from the beginning of your career. Then it becomes a tool to help you move on," she says.
Writtle Junior is one of 27 Essex primary and secondary schools that have taken part in a project to develop what are effectively records of achievement for teachers. With the local education authority already providing every newly-qualified teacher with a portfolio of professional development, these schools wanted something similar for more experienced staff.
"This group of schools believed quite strongly that there should be something that recorded and celebrated the positive, as opposed to the more negative comments we are faced with from elsewhere," says Paul Hughes, curriculum development adviser for Essex Advisory and Inspection Service, which managed the project.
Although it was up to individual schools to develop portfolios suited to their needs, the project identified a broad set of principles to guide them. These included: no teacher should be forced to keep a portfolio, ownership should remain with the teacher and competition to produce the "best" portfolio should be avoided.
While the schools in the project managed - after much debate - to agree on these principles, the materials they produced show sharp differences in focus. Some of the secondaries see the portfolio as a vehicle for linking individual development to the school development plan. The primary schools, on the other hand, tend to regard it more as a way of helping individual teachers achieve their career goals.
But at Writtle Junior School, headteacher Gwyneth Williams has found that what helps members of staff also serves as a management tool.
The school's portfolio includes pro forma sheets inviting teachers to say how useful they've found the courses they have attended. These comments help Ms Williams monitor and evaluate the school's in-service training, and plan courses.
The portfolio also has an indirect influence on the school's development planning. Unlike the sheets relating to in-service training, the sections designed to help teachers think about their classroom performance remains confidential. But the results can help inform the annual "professional dialogue" that Ms Williams holds with her staff to agree targets linked to the school's development planning.
A section on career development asks teachers what areas of interest they would like to pursue in the coming year and about their thoughts on possible career options. Individuals can raise these issues during their professional dialogue if they want to.
But the portfolio is not just about courses, targets and career goals. There is a section inviting teachers to say how they have helped develop other members of staff, including non-teaching staff, newly-qualified teachers and students on teaching practice.
The portfolio also gives teachers the chance to list their personal interests, record their contributions to the school's extra-curricular activities and include appreciative letters from parents, newspaper cuttings and other evidence of their professional achievements and activities.
As Gwyneth Williams says: "It's the whole person that makes someone a good teacher. Though a teacher must be competent, a really good teacher is more than just a competent one."
Introducing the Professional Development Portfolio into Your School, a manual published by the Essex Advisory and Inspection Service is available for Pounds 6.50 from EAIS Publications, Thaxted Centre, Clarance House, Watling Street, Thaxted, Essex CM6 2PJ.