The Physical Foundation of High-Speed Print
In the printing and graphic media industries, "Productivity" is measured by the speed at which the press can accurately transfer information onto paper. For a sheet-fed shop, the only metric that matters is how many "Sheets per Hour" pass through the delivery. However, for a roll-fed (web) press, the measurement is the "Linear Velocity" of the paper—usually in **Feet per Minute**. Understanding the relationship between these two metrics is essential for estimating the completion time of a project.
Defining the Cutoff Factor
The **Cutoff** is the fixed circumference of the printing plate cylinder on a web press. It determines the height of the final sheet. Unlike a sheet-fed press where the sheet size can vary, a web press has a "hard cutoff." If a web press is running at a constant foot-per-minute speed, a shorter cutoff will result in more "Sheets per Hour" than a longer cutoff, as more sheets fit within those feet of paper. Accurate cutoff data is the key to this converter's precision.
SPH: Sheets Per Hour
In the world of commercial lithography (Heidelberg, Komori, Manroland), **SPH** is the universal yardstick. Standard modern offset presses target 15,000 to 18,000 SPH. This converter allows planners to take those sheet-fed hourly rates and determine what the equivalent roll speed would be if the job were transitioned to a high-speed web or digital inkjet press (like an HP Indigo or RICOH Pro).
Professional Press Speed Reference
| Press Category | Avg. FPM | Avg. SPH (24") | Typical Use |
|---|---|---|---|
| Production Digital | 300 - 500 | 9,000 - 15,000 | Direct Mail / Short Run |
| Modern Sheetfed | 500 - 600 | 15,000 - 18,000 | Brochures / Packaging |
| Heatset Web | 2000 - 3000 | 60,000 - 90,000 | National Magazines |
| Coldset Web | 1500 - 2500 | 45,000 - 75,000 | Daily Newspapers |
Related Estimating Tools
Frequently Asked Questions
What is SPH in printing?
SPH stands for Sheets Per Hour. It is the standard unit of measurement for productivity on sheet-fed offset and digital printing presses.
What is FPM in printing?
FPM stands for Feet Per Minute. This is the unit used for web offset printing, where the paper is fed from a continuous roll (web) rather than individual sheets.
How does sheet length affect speed?
The same FPM (roll speed) results in a lower SPH if the sheet length (cutoff) is longer. This is a critical variable for estimating job turnaround times.