How are heteropteran forewings different from their hindwings?

In the insect order Heteroptera, the forewings and hindwings are distinct in both texture and structure.1

• Forewings: Often called hemelytra, these wings are characterized by a dual texture. The basal half is thickened and leathery, providing protection for the insect's body, while the apical half is a thin, membranous section with visible veins.12
• Hindwings: These are entirely thin, delicate membranes.12

When the insect is at rest, the forewings are folded flat over the abdomen. Because the membranous tips of the forewings overlap, they effectively cover and protect the more fragile hindwings, which lie tucked beneath them.12