Desktop 3D printers achieve multi-color printing by using multiple filaments, each representing a different color.
Most multi-color printers — around 90% — operate with a single nozzle, meaning they must unload the previous filament and load the next one during each color change.
To remove the residue from the previous filament, the printer extrudes a small amount of the new filament — a process commonly referred to as purging.
Pooping vs. Purge Tower Systems
There are two main approaches to this cleaning process:
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Pooping systems eject the remaining filament outside the printer.
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Purge tower systems print a small tower on the build plate and perform the cleaning process on that tower.
Although the methods differ, their goal is the same — to ensure clean, accurate color transitions. However, since this purging happens with every color change, it leads to extra waste and longer print times.
The Challenge with Tall Models
For tall models with color changes only at certain heights, the purge tower must still grow alongside the model.
Even during layers without any color change, the tower continues to build up — wasting both filament and time.
The Co Print Solution:
No Sparse Layers
in Orca Slicer
To solve this issue, Co Print officially supports a new feature in Orca Slicer: No Sparse Layers, now included in the Co Print profile under the Multi-Material tab.
When enabled:
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The printer no longer increases the purge tower height for every layer.
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Instead, it moves the print head down in the Z-axis only when a color change occurs, performs the purge, and then resumes printing.
This smart adjustment drastically reduces unnecessary tower height, resulting in shorter print times and minimal filament waste.
Real Results
With this feature activated, a print that normally takes 4.5 hours can be completed in just 3.1 hours.
And instead of wasting 40 grams, only 2 grams of filament are used for purging — a significant improvement in both efficiency and sustainability.
Conclusion: Smarter Multi-Color Printing with Co Print
The No Sparse Layers feature gives Co Print users a faster, cleaner, and more efficient multi-color printing experience.
Discover Co Print’s multi-color printing kits, compatible with almost any 3D printer, at
