Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective supply of electric current or selective application of magnetism to a printing or impression-transfer material for removing surface layer selectively from electro-sensitive material, e.g. metal coated paper
Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective supply of electric current or selective application of magnetism to a printing or impression-transfer material for removing surface layer selectively from electro-sensitive material, e.g. metal coated paper