Maruman Mnemosyne Notebook - Horizontal (Black) Designed for efficiency and precision, the Maruman Mnemosyne Horizontal Notebook is perfect for professionals, students, and creatives. Featuring 80 micro-perforated, acid-free graph sheets, this notebook provides a smooth writing experience, making it ideal for technical drawings, note-taking, and brainstorming. The sturdy twin-ring binding ensures durability and allows the notebook to lay flat for convenience. Key Features: 80 micro-perforated sheets for easy removal. Graph-style pages with 5 mm spacing for structured writing. Acid-free, fountain pen-friendly paper for a smooth writing experience. Twin-ring binding for durability and a lay-flat design. Compact horizontal format for portability and convenience. Specifications: Brand: Maruman Product Type: Notebook Size: 18.0 cm x 10.0 cm / 7.1" x 3.9" Cover Type: Softcover Cover Color: Black Cover Material: Plastic Binding: Twin Ring Paper Weight: 80 gsm Sheet Color: White Sheet Style: Graph (5 mm spacing) Number of Sheets: 80 Perforated Sheets: Yes (10.0 cm x 16.0 cm / 3.9" x 6.3") Paper Refillable: No Weight: 141 grams / 4.96 oz