The responsibility for collection preservation makes getting the specification right a non-negotiable requirement rather than a preference. I evaluated UV film specifically against conservation-relevant protection standards when sourcing for our UK museum after recognising the collection protection requirement was more demanding than general residential UV film descriptions were calibrated to address.
https://www.tintfit.com/shop/uv-protection provides UV protection window film with specification detail relevant to UK museum and conservation applications where the performance standard required goes beyond residential fading protection into the higher rejection levels necessary to meaningfully protect collections from light-induced degradation.