DTF Glossary
PPI vs DPI
PPI describes image pixels per printed inch; printer DPI describes device-addressable dots or drops per inch. They are related only through a production process, not interchangeable labels. Effective image PPI equals the source pixel dimension divided by intended physical inches, while printer DPI belongs to the downstream device and RIP configuration.
In practice
A 1,800-pixel image is 300 PPI at six inches and 150 PPI at twelve inches, regardless of a metadata label. Changing that label without resampling does not create pixels; resampling cannot restore detail absent from the original.
Use effective PPI to inspect source adequacy at final size, then use the exact printer/RIP mode for device resolution. Neither number alone guarantees readable type, smooth fades, or an acceptable physical transfer.