as the cellulose. This was a common process adopted in the USA. The product was frequently called Vellum, although this terminology can refer to a wider range of special papers. Due to the relatively high cost, this method of manufacture has largely disappeared. As with 2, by making a normal sheet of paper, which is followed by immersing uncut and unloaded paper of good quality in sulfuric acid for a few seconds. The acid converts some of the cellulose into amyloid form having a gelatinous and impermeable character. When the treated paper is thoroughly washed and dried, the resultant product is much stronger than the original paper. Tracing paper is resistant to oil, grease and to a large extent impervious to water and gas. The sizing in production will determine whether it is for laser printer or inkjet/offset printing. Tracing paper may be uncoated or coated. Natural tracing paper for laser printing is usually uncoated. The HS code for tracing paper is 4806.30. Tracing paper can be recycled and also can be made from up to 30% recycled fibre. Technical specifications Specifications of natural tracing paper: Smooth surface Non-ageing Acid-free Recyclable The follows are common standards for tracing paper though generally it is manufactured in densities over 60 g/m2: Application Traditional printing methods: letterpress, planographic / offset, silk-screen printing Laser and inkjet printing Processing: varnishing, laminating, punching, embossing, folding, scoring Drawing: ink, Indian ink, graphite, pencils Photographic and cinema lighting: diffusion filter for light sources to produce aesthetic effect End products Envelopes Mailings Flyer Coversheets Album cover dividers Business cards Greeting cards Posters Origami See also Inkjet paper Colour tracing paper: Tracing paper also can be solid or marble coloured. In modern times, colour tracing paper is normally used for decoratively for special printing purposes such as for brochures, menus, and invitations Parchment paper Wax paper Glassine paper Red rosin paper References External links Arjowiggins tracing paper product description Properties of different types of paper Tracing paper in Vietnam archive Usage guide of tracing paper Coated paper Visual arts materials Paper Drawing Printmaking Digital press Sewing equipment