A made to order helmet starts long before any material is cut. Measurements are taken, the intended use of the helmet is discussed, and a rider works with the maker to settle on a shell, lining and finish that suit them specifically, rather than picking from fixed stock sizes.
Sun and heat are the two things to watch for. Leaving a helmet on a dashboard or in direct sun for long periods will dull and eventually crack leather trim, so a helmet bag or a shaded spot makes a real difference over the life of the helmet.
A clean visor is a safety item as much as a comfort one, since scratches and haze scatter light and make it harder to judge distance in low sun or at night. Clean a visor with lukewarm water and a soft cloth, and avoid dry wiping, which is what causes most fine scratches in the first place.
Any impact, including a helmet dropped from a moderate height, can compress the inner liner in ways that are not visible from outside. A helmet is designed to absorb one significant impact by sacrificing that inner material, so a helmet involved in a crash should always be replaced, not inspected and reused.
To see the current range built this way, visit link homepage.
Certification is not a formality. It is the baseline that separates a genuine protective helmet from something that only looks the part. Any helmet worth wearing on the road should carry a current, verifiable certification.