Issues with exporting as a PNG file

[phyllis_9070]

I am trying to create PNG files for sublimation printing.  After creating a design in Illustrator, I am exporting as a PNG (300 dpi, transparent background).  The PNG files are alway the incorrect size.  I have tried exporting the artboard AND the asset from the artboard, and both have the same result.  I only recently started using Illustrator again after a few years, so I assume there is something I am missing.  Any help would be appreciated!

[Bobby Henderson]

Many applications will import PNG images at a 72ppi setting. Something intended to be 300ppi could end up being over 4 times the intended physical size when placed.

Also, why use the PNG format? It's limited to RGB color space. PNG is great for web graphics and works pretty well for other purposes involving electronic screen display. For print output PNG is not so great. If your print setup supports the TIFF format that would be a better alternative. TIFF can support both RGB and CMYK (among other color modes) as well as include color profiles. TIFF also supports alpha transparency like PNG.

I try to opt for using PDF for print output whenever possible since it supports both pixel-based and vector-based content. Transparency effects are supported. The downside with PDF is not all printers do a good job outputting it. If they don't have an Adobe certified PDF print engine problems can occur. That makes TIFF a decent fall-back option.

[phyllis_9070]

Thanks!  I used PNG because everything I read regarding sublimation said that is the correct file type, and that RGB was the preferred mode.  Sounds like  I have a lot to learn about files used for sublimation... Any advice on good resources?

[Bobby Henderson]

This forum is a good resource. There's a lot of other stuff, both good and bad, across the Internet. I'm not sure why PNG would be recommended as a default format to use in dye-sub printing. My guess is the people making the printers and print software are trying to simplify work flow details for the end users. Maybe the thinking is since PNG has certain limitations there are fewer things to mess up. Not everyone doing print work knows the various pros and cons of different file formats.

Generally, the contents of the document should dictate the type of file used to output a print job. If the document is just a photograph or an entirely pixel-based image created in Photoshop then a PNG image might suffice. I'd still opt for a TIFF image rather than PNG because I know the image's resolution settings and color profile will be honored. If the document has a mix of pixel-based imagery and vector-based elements (logos, graphical items, etc) PDF will be a better choice since the vector-based elements will print at the maximum resolution the printer supports. I would compose layouts that have a mix of pixel-based imagery and vector-based elements using Adobe Illustrator. If it's a multi-page docment InDesign might be a better choice. Both applications would be exporting a PDF to send to the print application or RIP.

The type of printer being used should dictate the color mode, be it CMYK or RGB. If the printer has extra ink colors, such as Light Cyan and Light Magenta, it can be better to compose documents in RGB color space. But gamut limits do still exist. No printer can output the entire RGB color range. Some caution must be used when working in that color space. Printers with extra ink colors can do a better job simulating spot colors, such as those from Pantone.

[phyllis_9070]

Thanks!  I will try using TIFF and see if it works for me. I really appreciate your taking the time to help!  Like I said - I have a lot to learn...

[Ton Frederiks]

RGB is a good color mode for dye sublimation.  Instead of using the CMYK numbers limited to a printing press, you can take advantage of the larger gamut available in printers using more inks than the traditional 4 CMYK printing press inks.

PNG files exported from Illustrator do not have an ICC Profile attached, a long standing bug that has been there for years.

You need to correct that in applications like Photoshop or Mac Preview and assign the color profile that was used in your Illustrator document.

Regarding the size, what app is showing the wrong size? It could be that the app is not reading the metadata.

[phyllis_9070]

I am exporting the files to my PC, and printing from the exported file.  I did some more "experimenting", and even if the size of the design shows the same on the exported file, the printed design is a different size.  Sounds like something on my end?

[Ton Frederiks]

Which app do you print from?

[phyllis_9070]

Not sure I understand...  I am just printing from the file that I exported.  Is there an app I need to use for this?  

[phyllis_9070]

OK - hold on a second.  If I open that file with Illustrator and print it from Illustrator, it prints correctly.  Is that what you are saying?  

[Ton Frederiks]

I wondered which app you opened the file in to print from. If that is Illustrator and you print from the same kind of file file you used create the export, it should print fine.

[phyllis_9070]

That is the solution! (YAY!)  I was just skipping that step before printing.  Thank you so much for your help - I appreciate your time and patience.

[Ton Frederiks]

Good to hear you've got it working.