This Wilton round No. 2 tube (tip) is a seamless stainless steel nozzle that is perfect for piping heavier lett... This Wilton round tube (tip) No. 1 is ideal for huge lettering, dots, and a snail's trail. It's made of heavy duty aluminum with a black oxide finish for long-lasting durability. The No. 1 tube is available in different sizes from 1/4 inch to 1-inch diameter. It's best to start with a size smaller than the hole you are trying to create and then switch to a larger one if needed. For example, if you want to write in block letters on a sign, use the smallest size tube that will still allow you to do so. Writing with a wider nozzle creates a smoother line and is better for fine writing. The thinner the tip, the sharper the point and more likely it is to cut into the surface you are writing on. There are many other types of writing tools out there, such as pens, markers, graffiti artists' supplies, etc., but these are some of the most common ones used by sign writers.