With the right preparation wigs can look totally real. Normally this requires the wig be made to measure requiring a shape-taking appointment, then a foundation fitting to ensure the lace fits and then, once made, the wig needs to be fitted to the artist, cut if necessary, styled (twice), the lace trimmed. The third and final fitting should be done at the very latest the day before the artist works, ideally a few days before. The whole process normally takes 5 weeks.
For "Incendiary" I had two wigs made for Michelle Williams. After delivery I shadowed the roots by painting them myself over the week-end before filming. Also note the "skin deep" parting which is essential for naturalism. Not once was the lace visible in the film.
Sometimes the period 'dressing' of a wig can make it look more solid, but where possible I try to not let the period dressing get the better of some natural movement and a quirk or two that will help it look real. Sometimes the script will specify a colour, as did "The Thirteenth Tale" - which called for "a colour not known in nature", for Vanessa's character, the subtext being the character had her hair dyed all her life long.
Designer Naomi Donne tasked me with putting together the look for "God". I was given two wigs, two beards and a reference she had agreed with Nick Hytner and I was given a day to prep the look. On the left you see the wig with a nice 'skin deep' parting and on the right you see "God" greeting Maggie Smith's character into Heaven. Both Naomi and Nick were very pleased.
For "Marple" I was hired especially to solve what had been a bit of a wig issue on the previous series. Due to the long schedule I had two wigs made which meant that one could be dressed during the day while the other was being worn. This is important so that the make-up artist who looked after Geraldine could wrap Geraldine and be prepped for the next day quickly. There was not time to dress the wig each night - as the trucks we were always on the move and we needed to step off pronto without doing much, if any overtime. The boys had trucks to move. It's a thought isn't it! Sometimes there just don't seem to be enough hours in the day.