Perforated Metals
Description includes wire diameter, hole size, can come in rolls and/or sheets, size of roll and/or sheet, or cut to specific size, different material that it comes in.
Complete Perforated Metals List (PDF)

Square Hole
1/2" Square, 16 Gauge, Plain Steel Perforated

Round Hole
1/4" on 3/8", 16 Gauge, Plain Steel Perforated

Decorative - Slotted
1/8" x 3/4" Oblong Slot Side Staggered, 16 Gauge, Plainsteel Perforated

Decorative - Grecian
Grecian, 20 Gauge, Plain Steel Perforated

Custom - 1/4" Copper Perforated
1/4" Copper Perforated