Drip edge comes in two types; A "T" shape drip edge that extends out over the edge of the roof decking. Particularly useful with bracketed half round rain gutters which are held out a small distance from the fascia / gutter board. And "L" shape drip edge, which hugs the edge of the roof deck and is used most often with flange back rain gutters.
Home store drip edge is usually made of aluminum or galvanized steel.Sometimes painted, usually white or brown. The aluminum is usually the thinnest grade available. Very flimsy and easily dented. The galvanized drip edge is also of the lightest guage and electroplated with a thin layer of zinc plating.
Heavier guage drip edge is available at many roofing supply stores. They will also carry differing sizes of drip edge to best match the intended use.
Some roofing contractors, the good ones, will have sheet metal brakes to fabricate their own drip edge to fit the differing pitch / angle of a particular roof.
When roofing with slate or tile roof shingles, copper, lead coated or zinc coated copper, or stainless steel drip edge should be used to match the durability and lifetime of the roof materials.
Drip edge for metal roofing should have a waterstop hem on the roof side to prevent wicking water from reaching the roof decking.
Special tools and techniques are needed when installing metal drip edge to a curved roof surface. For example, a professional roofer with sheet metal experience should be called to fabricate and install drip edge for this "eyebrow" dormer.