I'm using InDesign for invitations. Can I use png florals in my designs? Will they print properly at a print company?
First: Always consult with your vendor about how they require their file submissions. PNG format can be used for printing, and very often are used with perfectly acceptable results, but it may not be the most optimal format. I assume you want to take advantage of the PNG's transparency, which should be fine, but that comes with some baggage. There are three caveats to consider before using a PNG in a print layout:
- Resolution: the PNG format is largely used for web graphics, so be sure that the PNGs you are using are sufficiently high resolution (optimally 300 effective resolution). Google "effective resolution indesign" if you aren't familiar with that term.
- Transparency: Some printer's RIPs (the computer software/hardware that processes files for printing) may not process transparency well, especially if the layout also contains spot swatches.
- Gamut: PNGs only support grayscale or RGB, not CMYK. Some printers require files to be submitted in CMYK only.
One way to mitigate many of the issues associated with PNGs in print layouts is to export using the PDF/X-4 standard.
In general, if it is a simple digital print, you will be fine with whatever format or color mode.
For a more specific situation, when exporting your InDesign work to PDF you can convert the images to CMYK using a specific setup including the color profile.
For more advanced stuff, aka commercial print, where you need to print thousands of copies and you do not want surprises, you can convert your images prior to inserting them in InDesign.