Direct answer: Image quality depends on pixel dimensions at the intended output size, source quality and viewing distance. PPI describes image pixels per inch at a chosen print size, while printer DPI describes output dot placement. They are related but are not the same measurement.
Engineering Principles and Components
| Topic | Function | Practical check |
|---|---|---|
| Pixel dimensions | The number of pixels in an image. | A small image enlarged substantially can reveal blur or pixelation. |
| PPI at output size | Image pixels divided by the intended printed inches. | Check separately for width and height at final dimensions. |
| Printer DPI | A specification of printer output placement or a print mode. | Do not treat it as the same as the source image PPI. |
| Vector artwork | Uses scalable paths for suitable shapes and text. | Embedded photographs still have their own resolution. |
Practical Shop Checklist
- Obtain original artwork rather than a compressed messaging-app preview.
- Set the final print size and inspect the source image at that size.
- Ask the print provider about bleed, safe area, file format and type treatment.
- Approve a physical proof at the intended viewing distance when detail matters.
Related Engineering Guides
Start with how a piezo printhead works and digital inkjet machine anatomy. For a machine-specific question, share your model on our contact page.
Frequently Asked Questions
What is the difference between PPI and DPI?
PPI describes image pixels per inch at output size; DPI refers to printer dots or output placement.
Does changing a file number add real detail?
Simply changing a resolution value does not recreate missing detail. Resampling can add pixels, but it cannot guarantee original detail.
Are vector files always sharp?
Vector shapes scale well, but embedded raster images still depend on their pixel dimensions and source quality.
What resolution should a large banner use?
It depends on final size, source quality, viewing distance and printer requirements. Ask the print provider and inspect a representative proof.
Can I use a photo sent through a messaging app?
Compressed previews may lack detail. Request the original file where possible.
What is bleed?
Artwork extended beyond the finished cut edge so small cutting variations do not leave unintended gaps.
How do I inspect tiny text?
Check the file at output size and proof it on the intended substrate and equipment.
