Grade 588 Grade 1573. A fast filter paper with high wet strength. It has a very smooth surface, making iteasy to scrape or wash off precipitate. Resistant against: sulfuric and nitric acid solutions (up to 40% at 50°C), hydrochloric (up to 10% at 100°C, 20% at 60°C, 25% at20°C) and alkalis (up to 10% at 20°C).