PPGI vs PPGL — Which Coated Steel Substrate to Choose

The two share the same paint finish on top — the real difference is hidden underneath. Both are pre-painted steel coils, but they start from different metallic coatings, and that changes how they perform, how long they last and what they cost.

The Short Answer

PPGI (Pre-Painted Galvanized Iron) — a zinc-coated steel base, then painted. The everyday workhorse for indoor panels.
PPGL (Pre-Painted Galvalume) — an aluminum-zinc alloy base, then painted. Built to shrug off humidity and coastal air.

Side-by-Side Comparison

Point	PPGI	PPGL
Metallic base	Zinc (hot-dip galvanized)	Aluminum-zinc alloy (approx. 55% Al / 43.5% Zn / 1.5% Si)
Corrosion resistance	Good for indoor, dry use	Stronger — holds up better in humid, coastal or industrial air
Surface look	Smooth, uniform	Fine metallic spangle visible through some finishes
Cost	More economical	Slightly higher price for the extra protection
Best fit	Indoor appliance panels, general interior use	Coastal regions, outdoor or semi-outdoor parts, high-humidity sites

How to Decide in Practice

Start with one question: where will the part live?

Indoor appliance cabinet, dry storage — PPGI is almost always the right balance of cost and performance.
Near the coast, a cold room with condensation, or an outdoor AC unit — PPGL buys you longer service life for a modest premium.

If you are unsure, tell us the appliance type, the installation environment and how long the product is expected to last. We will recommend the substrate that fits — without overselling you the more expensive option.

A Few Numbers for Reference

Both are available in thicknesses of 0.12–1.2 mm and widths of 200–1500 mm.
Zinc coating on PPGI ranges from 30 to 180 g/m² depending on requirement.
Paint systems — PE, SMP, HDP or PU — are the same for both, chosen by application.

Ask Which One Fits View PPGI Coil

PPGI vs PPGL: How to Choose

The Short Answer

Side-by-Side Comparison

How to Decide in Practice

A Few Numbers for Reference