Pinstripe suits are very tricky to deal with , The most expensive element of a suit, by far, is the fabric used to make it.
The first thing to note is the balance and symmetry of the pinstripes on the lapels. Here the cutter left the perfect amount of space between the outer stripe and the edge of the lapel – allowing the line of the lapel to mimic the spacing and proportions of the stripes.
The thing about a dart is that it eliminates fabric from the underside, which in turn distorts the proportion of the pinstripes (or any other pattern on the fabric). Take a look at the midsection of this beautifully cut suit by Michael Andrews Bespoke. The pinstripes are carefully treated to accommodate the darts, keeping them perfectly symmetrical and parallel as they are brought in the shape the jacket. This effect also further enhances the suppression effect of the jacket.
Lastly, another area to examine is the setting of the sleeves into the shoulder.
A good cutter will do his best to match as many stripes as possible – keeping in mind that it’s physically impossible to get the pinstripes to match perfectly here. (Due to the curve of the armhole, the distance between the angled pinstripes on the shoulder is wider than the straight ones on the sleeve.