# Choosing the Right Piston Colour Depending on your material and nozzle size, you may need to switch piston colors to achieve optimal performance. Selecting the appropriate piston for your cartridge is essential for consistent, reliable results. We offer two piston options: **white (standard fit)** and **red (tight fit)**, each suited to different dispensing conditions.

#### White (standard fit): White pistons are the standard piston color used in our cartridges. They generally perform well with medium- to high-viscosity materials, such as the standard inks we stock. As a rule of thumb, select a white, normal-fit piston when dispensing your material at pressures below 3000. #### Red (tight fit): Red pistons are considered “tight fit” and provide a stronger seal against the cartridge wall. As a rule of thumb, select a red, tight-fit piston when dispensing your material at pressures above 3000. A red piston is often required if you are dispensing our stocked inks with small (<150µm) Nordson straight barrel nozzles. Red pistons should also be considered when you are printing with a relatively thin materials. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.voltera.io/docs/nova/learn-nova/working-with-inks/choosing-the-right-piston-colour.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.