Marking or dulling of tin plate

Claim 1

IN THE PRODUCTION OF TIN PLATE BY ELECTROLYTICALLY DEPOSITING TIN ON A BASE METAL SHEET AND THEREAFTER HEATING THE SHEET TO AN ELEVATED TEMPERATURE FOR FUSING THE ELECTRODEPOSITED TIN, THE IMPROVEMENT WHICH COMPRISES APPLYING TO A TIN COATED SURFACE OF THE SHEET INTERMEDIATE THE ELECTRODEPOSITION AND FUSION STEPS AN AQUEOUS SOLUSELECTED FROM THE GROUP CONSISTING OF THE ALKALINOUS SELECTED FROM THE GROUP CONSISTING OF THE ALKALINOUS METAL CHLORIDES, BROMIDES, IODIDES , SULFATES, CARBONATES NITRATES AND CHROMATES, SAID SALT BEING STABLE AT THE ELEVATED TEMPERATURE OF THE FUSION STEP, AND THE AMOUNT AND CONCENTRATION OF THE SOLUTION APPLIED BEING SUFFICIENT TO PROVIDE AT LEAST 100 MILLIGRAMS OF SAID SALT PER SQUARE FOOT OF TREATED SURFACE WHEREBY THE TIN PLATE FOLLOWING THE FUSION STEP IS PROVIDED WITH A DULL SURFACE MARKING AND SAID SILICATE PREVENTING LOSS OF THE SALT FROM THE SHEET BY DECREPITATION AND SPALLING DURING THE FUSION STEP.