Your character has to bite out his tongue, then cut his throat and die drenched in gore. How is he to do that convincingly without damaging himself? First, the tongue. Unfortunately, rubber ones bounce, so that’s not an option. Calves’ and pigs’ tongues have the right consistency, but they are huge. So you cut two inches off one previously owned by a pig, give the actor a little bag of stage “blood” to store inside his cheek, and bite at the crucial moment, then leave the rest to characterisation.

An adapted colostomy kit, with holes in the tubing, does a turn for the spurting throat. A bag of nicely thinned “blood” is worn around the waist, so a little squeeze sends the contents squirting out over the actor’s ruff.

Brenda Leedham, head of wigs and make-up at the Royal Shakespeare Company, is pleased with her department’s solutions, except that a consignment of pigs’ tongues had to be ordered for the season, stored in the wig room freezer and prepared for each performance of Thomas Kyd’s The Spanish Tragedy. “And” - she shudders - “we’re all vegetarian in here.”

All this gory trickery is shown in some detail in the second programme of Behind the Scenes at the RSC, two 25-minute documentaries in Channel 4‘s English Programme series. Designed for 14 to 16-year-old drama and theatre-studies students, the programmes also provide careers information and the sort of little-known material audiences of any age find fascinating.

This is not, admittedly, a warts-and-all expose such as The House, which gleefully revealed the least attractive secrets, the backbiting and snobbery of the Royal Opera House. Here are people committed to pulling together in a creative team, determined to make the most of their talents, and always with the same aim - to stage the best possible production of the play they happen to be working on.

If that seems idealistic - no rivalry, no disputes, ever? - in this case it doesn’t matter. Much better to let us learn how a designer presents ideas, how a tree is made to look life-like, why “old” costumes have to be newly made, and just how uncomfortable it is for Ariel to wield stage-wide wings in the “flies”.

Tom Piper, designer of Measure for Measure, Much Ado about Nothing and The Spanish Tragedy, shows how he makes a scale model of each set and briefs the production departments that will put his ideas into practice. Carpenters, painters, costume-makers, dyers and make-up staff all set to work - Measure for Measure represents 8,000 hours of work over eight weeks.

Each design presents unique challenges. The stage surface for the current Tempest is covered with pebbles. But pebbles are heavy and noisy, so each “stone” is painstakingly cut from foam rubber pellets, then glued, painted and fire-proofed - safety is a constant factor. Ariel (Scott Handy) has to be strapped into his wings high above the stage, but he is perched on a tiny bicycle seat which, he says, brought tears to his eyes until it was padded. As Caliban, Robert Glennister (who inhabits a spectacular polystyrene and fibreglass conch) is covered in grey-black. “It is,” he says, “the sort of make-up that takes two hours to apply and four days to get off.”

That life-like tree in Much Ado about Nothing was created by taking a mould of a real tree and making fibreglass castings. Alex Jennings, who plays Benedick, shows the scenic artists how he needs to climb into the branches. Footholds are built in accordingly.

Everything prepared for an RSC production has to last two years from the first night in Stratford to performances in London, and on tour. Fabrics have to be resilient - every costume is washed or cleaned after every performance. And that is why old clothes cannot be used. Anything that has to appear worn is attacked with a cheese-grater but then stitched to prevent further, unplanned, damage.

These are clearly-presented programmes, full of articulate enthusiasts, which could hold their own in peak slots. For now, they are a useful resource - for teachers of text as well as skills. It is just a shame there are no plans for any more, about lighting and sound or the director’s role.