Snowden Designers Cartridge Paper 300gsm. A4. Each. Our top of the range, off-white, superweight cartridge is a professional quality paper which is wood-free, has a neutral p H & has a matt surface. The exceptional surface quality & heavy grammage means Snowden excels in most applications including illustrative design & sketching with pastels, charcoal & graphite together with screenprinting, litho & watercolour.