How to Quickly Judge the Quality of Thermal Paper
I. Visual Inspection:
1.Paper surface cleanliness
High-quality thermal paper features a smooth surface free of impurities, obvious white specks or black spots, with an evenly coated layer. Inferior paper may have dust, scratches and an uneven coating thickness.
2.Color and transparency
Unprinted thermal paper should present a matte texture of pure white or slightly yellowish. Paper that is overly white and shiny may contain an excessive amount of fluorescent agent; paper with strong reflected light also has an overdose of fluorescent powder, which is prone to aging with long-term use. Hold the paper up to the light: a qualified thermal paper has no obvious uneven coating defects with light and shade differences.
3. Edge neatness
Premium thermal paper has neat, burr-free cut edges and is not easy to shed powder. Otherwise, the printer’s rubber roller and print head will be worn out.
II. Simple Tests: Test the Imaging & Stability
1.Nail scratch test
Scratch the paper surface firmly with a fingernail. A high-grade thermal paper will leave a clear, uniform and dark scratch mark. A faint, intermittent scratch mark, or a large blackened area caused by a single scratch, indicates a poor coating formula.
2.Simple high-temperature test
Place the paper close to the outer flame of a lighter (or the wall of a cup with hot water) for 1-2 seconds. High-quality thermal paper achieves uniform imaging with sharp and clear edges after heating. Inferior paper will show bleeding blackening or mottled imaging.
3.Sun exposure comparative test
Apply a highlighter pen on the printed thermal paper and place it under direct sunlight (this accelerates the photoreaction of the thermal coating). The paper that turns black the fastest indicates a shorter shelf life of the printed content.
4.Printer test
Print a sample page and check the shade and uniformity of the imaging.
