Spunbond Polypropylene (PP) is the dominant choice for nonwoven bags. It offers:

Excellent Cost-Effectiveness: Relatively inexpensive raw material and efficient production.

Good Strength-to-Weight Ratio: Durable enough for shopping bags despite being lightweight.

Printability: Takes ink well for vibrant logos and designs (using flexographic, screen, or digital printing).

Water Resistance: Naturally repels water (though not waterproof).

Reusability: Can be used multiple times.

Spunbond Polyester (PET): Offers higher strength, better temperature resistance, and UV stability than PP, but is usually more expensive. Used for more durable or outdoor bags.

Needle Punched: Creates a thicker, felt-like fabric. Used for heavier-duty reusable bags, promotional tote bags, or bags needing more insulation/texture. Often made from PP or PET.

SMS (Spunbond-Meltblown-Spunbond): Primarily used for medical/insulated bags due to its barrier properties. Overkill for standard shopping bags.

Thermobonded: Similar to spunbond but uses heat to bond fibers. Can be made from various polymers.

Weight (GSM - Grams per Square Meter): Crucial for bag strength and feel.

Lightweight Bags: 40-60 GSM (Common for simple giveaway bags).

Standard Shopping Bags: 60-80 GSM (Most common balance of cost & durability).

Heavy-Duty/Reusable Bags: 80-120+ GSM (Thicker, sturdier, more expensive).

Color: Most commonly White (best for printing), but also available in various colors (black, blue, green, pink, etc.). Can be dyed or made from colored fibers.

Finish: Standard, Anti-static, Hydrophilic (water-attracting), etc.

Cost-Effective: Cheaper to produce than woven fabrics or paper bags (at scale).

Reusable: More durable than paper, can be used multiple times.

Customizable: Easily printed, cut, and sewn/sealed into various shapes and sizes.

Eco-Friendly Perception (Debatable): Marketed as reusable and recyclable (though recycling infrastructure is limited). Biodegradable options (PLA, etc.) exist but are less common/more expensive. Significantly reduces plastic use compared to single-use plastic bags.

Strong Marketing Tool: Large printable surface area for logos and branding.

Recycled Content: Fabrics made partially or fully from recycled PP/PET bottles or industrial waste are increasingly available.

Biodegradable Options: Fabrics made from PLA (corn starch) or other biopolymers exist but are less common, more expensive, and require specific composting conditions.

Certifications: Look for fabrics with certifications like Oeko-Tex Standard 100 (safe from harmful substances), GRS (Global Recycled Standard), or ISO 14001 (environmental management).

Major producers are located in China, India, Turkey, Europe, and North America.

Key factors when sourcing: GSM consistency, roll width, color fastness, printability, tensile strength, and supplier reliability/certifications.

In summary: For nonwoven shopping bags, Spunbond Polypropylene (PP) in the 60-80 GSM range, typically white, is the standard, cost-effective, and versatile choice. Heavier weights (80-120+ GSM) or alternative materials (PET, needle-punched) are used for more durable or specialized bags. Sustainability features like recycled content are increasingly important.