Umbrella marketing loves vague words like ‘reinforced’ and ‘windproof’. Here is what the materials actually mean.
Aluminum
Light and cheap. Ribs bend permanently on first inversion.
Fiberglass
Flexible — it bends instead of breaking, which is good, but the joint hardware around it is still weak plastic and rivets.
Stainless steel plate and rod
Heavier on the spec sheet, vastly stronger in a storm. Our frame survives being stepped on. The trade-off is a few extra grams — we think never buying another umbrella is worth it.