Done. Here is the SEO article focusing on "Sheet", written naturally without AI identifiers, within the 400-word range:

The term "sheet" itself seems simple, but it represents a vast category of essential materials integral to countless industries and everyday applications. From the paper you write on to the metal forming your car's body, sheet materials are fundamental, versatile building blocks.

Sheets are defined by their form: thin, flat pieces where thickness is significantly less than length and width. They can range from fractions of a millimeter to several inches thick. Importantly, they are available in a staggering array of substances, each chosen for specific properties:

• Metal Sheets: Perhaps the most recognized industrial type. Steel, aluminum, copper, brass, and titanium come in sheet forms for fabrication into everything from aircraft skins and car panels to appliances, machinery, ductwork, and architectural cladding.
• Polymer Sheets (Plastics & Acrylics): These include sheet materials like polycarbonate (known for impact resistance), acrylic (clarity like glass), PVC (versatile and chemical-resistant), HDPE (chemical/temperature resistant), and more. Applications span signage, skylights, protective barriers, displays, medical devices, and packaging.
• Rubber & Silicone Sheets: Gaskets, seals, padding, vibration dampening, and protective mats often start as a custom-cut rubber or silicone sheet. Their flexibility and resilience are key.
• Glass Sheets: Beyond windows, specialty glass like laminated, tempered, or low-e glass comes in sheet form for safety, energy efficiency, and unique architectural needs.
• Composite Sheets: Engineered materials combining fibers (like fiberglass or carbon fiber) with resins result in strong, lightweight sheet products used in aerospace, automotive, and marine industries.
• Fibrous Sheets: Paper is the classic example, but this category includes non-wovens, fabric, felt, cork, and even woven fiberglass mats used in laminating.

Why Choose Sheet Materials?

• Manufacturing Flexibility: Sheet stock is the ideal starting point for processes like laser/waterjet cutting, CNC machining, bending, stamping, punching, and forming. This allows complex or customized parts to be made relatively easily.
• Surface Properties: Sheets provide consistent, large, flat surfaces, crucial for applications needing smooth finishes, adhesion points (like graphic mounting), corrosion-resistant coatings, or specific textures.
• Variety & Customization: With numerous material types, thicknesses, surface finishes (polished, textured, coated), and the ease of cutting-to-size, sheet solutions can be precisely tailored.
• Protective & Functional: Plastic sheet serves as hygienic barriers or display surfaces. Rubber sheet seals and cushions. Metal sheet shields and provides structural integrity. The functional range is immense.

Whether it’s an inconspicuous backing layer or the prominent structure of a building, sheet materials deliver essential properties – strength, flexibility, flatness, smoothness, transparency, resilience, and weather resistance – with remarkable adaptability. They are truly fundamental elements of innovation, construction, and everyday life.