Gel ink, favored for its smooth application and vibrant colors, can bleed through paper under certain conditions. This tendency is largely influenced by the paper's thickness and quality. Thinner, less absorbent papers are more susceptible to bleeding, as they cannot adequately contain the ink. Conversely, thicker, higher-quality papers significantly reduce the risk of bleeding, offering a better writing experience. Additionally, the amount of pressure applied while writing can affect bleeding; a lighter touch may help minimize it. Considering these factors is crucial for those seeking to maintain neat, bleed-free writing or artwork. It's advisable to test the gel pen on a specific type of paper before committing to a project.

Red oxide of iron, commonly known as iron(III) oxide, is a chemical compound with the formula Fe2O3. It is one of several iron oxides and is a major component of rust, contributing to its reddish color. This compound occurs naturally in minerals such as hematite, which is used as an iron ore, and has significant applications in various industries. In painting, red iron oxide is valued for its durability and color fastness, making it a popular pigment for protective coatings, primers, and art. It also serves as a raw material in the production of steel and other iron-based products, acting as a source of iron in the blast furnace process. Additionally, it finds use in the cosmetic and pharmaceutical industries as a colorant. Its magnetic properties are exploited in the field of data storage as well.

To stop a leak in a PVC pipe joint, Teflon tape, also known as PTFE tape, is commonly recommended. This tape is specifically designed to create water-tight seals in threaded joints. However, for a PVC pipe joint leak, a more effective solution is often the use of PVC solvent cement. This chemical solution essentially 'welds' the PVC at the joint, creating a permanent bond that prevents leaks. Before applying, ensure the area is clean and dry. Apply the solvent cement as per the manufacturer’s instructions, typically around the outside of the pipe and inside of the fitting, then join and hold for a few seconds. For larger or persistent leaks, consider replacing the damaged section of pipe. Always follow safety instructions when working with chemicals.