I was at Zohreh in midtown earlier this week for a blazer fitting (yes, we shall have a series on the experience) and was discussing my dilemma to line or not line the blazer. As I was planning to have it for summer use not having a lining seemed most logical, as it would allow for greater air circulation which would help moderate my body temperature and perspiration. However, Sean, the proprietor, steered me toward a lining.
Sean brought up a few points that I had until then mostly discounted. The first of which was that the lining helps with the drape of the jacket. I had previously thought that it would help because the lining would add weight. However, Sean pointed out that it helps by keeping the fabric off the shirt and any perspiration on said shirt which could cause the jacket to stick to the shirt would no longer be an issue. In essence, the lining allows the jacket to flow and slide more freely over the wearer, giving a more natural look to things. His second point was that it increases the longevity of the jacket. Which I had previously thought was the case because it would protect the inside of the fabric from the body, but this is only part of the reason. Sean pointed out that it is mostly because the lining takes much of the stress from the wearers movements, for instance when the wearer stretches or moves his arms around. When there is no lining all of the stress is transferred to the fabric of the jacket. But I have also talked to other tailors (Sean is not a tailor, he is a stylist) who have discounted these points. So perhaps back to square one. But I leave it as this: it is all a matter of preference really, but with all decisions of this ilk it is best to have too much than too little to think about. In short, I decided on a lining.