Overhead projector screens are fiendish contraptions, closely related to deckchairs and ironing boards, specially designed to trap fingers and skin shins. Once you’ve got the wretched thing up, you discover it’s in the wrong place, and the struggle resumes. In a classroom, it’s probably not worth the effort, because the three-legged monster takes up so much room there’s none left for children.

One answer, of course, is to campaign for a wall-mounted whiteboard: you can project on to it (as in the Grammar for Writing video), and use marker pens to highlight and annotate the enlarged text. Well, that’s the theory - as long as light from the windows doesn’t mean that half the class is craning to avoid reflection (then you have to campaign for blinds as well).

There is now another option: Rahmqvist now produces detachable A1-size sheets of white static film that adhere to any vertical surface. Three of these sheets make a perfect whiteboard screen, which you can position anywhere in the classroom and remove when not in use. Rahmqvist estimates that the “Film Fix” sheets maintain their fixative powers for 30 to 40 uses (contact office@rahmqvist or 01784 439888).

You could also do what I’ve seen in several classrooms recently: choose a suitable section of wall (quite high, where everyone can see) and paint it white.

It’s worth struggling with the logistics of all this because of the best thing about overhead projectors: they allow you to share a wide variety of text, pictures and diagrams with your class at a size they can all read from their seats. This is important, because good shared teaching relies on a shared experience. Children who are focusing on individual text-books or photocopied sheets aren’t “with you” in the same way: when their heads are bent over desks, you can’t make eye contact, and your hold on the class is lost. Successful interactive teaching requires that the whole class faces the front, their gaze shifting only between the shared focus and you. An hour or so solving the problem of the screen will pay long-term dividends.

From art to writing frames Stuart Marsden, Year 3 teacher and head of creative arts at the Vineyard school in Richmond-upon-Thames, is so enthusiastic about this way of teaching that the head felt compelled to buy an extra projector for his year group.

“I use it in almost every subject area, but it’s particularly good for the shared sessions of the literacy hour. For shared text, I only hae to photocopy one sheet on to acetate, rather than 30 - then there’s only one sheet to store. For shared writing, you can work facing the class, maintaining eye contact, rather than turning away to write on the board. For teaching handwriting, I have one transparency prepared like a lined page from the children’s handwriting books, and I write over the top of this on another acetate.

“You can also invite children to write on the projector: this is closer to their normal writing experience than writing on a board. They can use similar-sized pens and their normal writing size. Their work is projected up where everyone can see it easily. Or you can photocopy a good piece of written work, or “handwriting of the week”, on to acetate and invite the child out to talk about how they achieved it.

“I use transparency writing frames constantly, in literacy and across the curriculum - science experiment, timeline and spider diagram templates. For science and maths, you can get some marvellous commercially-produced transparencies - clock faces, number grids, movable number tiles, thermometers - and lots of materials for number games, including transparent and opaque counters, which black out certain numbers for you.”

OHT maths materials available from Hope Education 0870 2433400

STUART’S TOP TIPS

* Keep the projector on a trolley - it’s easy to store and to move about when you’re adjusting the text size for children to read.

* When you annotate a text or use an acetate template, don’t write directly on the acetate. Put another blank acetate sheet over the top and secure with paper clips. That way your originals can be used again.

* Buy special acetates to use in your computer’s printer. They’re a bit more expensive than photocopier transparencies, but you can download excellent material straight from the Internet. Try www.nationalgallery.org.uk for pictures and www.pro.gov.uk (the Public Records Office) for facsimiles of historical documents.

* Leave a good margin round any writing or pictures on the acetate sheet - there can be practical problems projecting a whole A4 sheet.

* Transparency pens last longer than whiteboard pens so are worth the investment - they’re also a better size for children to write with. Use wet wipes to remove old writing.

* Keep acetates in ring binders, where they’re easy to access. Use them in clear plastic wallets and they’ll stay thumbprint-free.

* Don’t forget copyright laws - there’s a form to fill in declaring what has been photocopied. It’s the same for transparencies as for normal photocopying.