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How to make an high quality image for print.

Posted: Wed Dec 15, 2010 10:48 pm
by Uolter
I don't know if someone dealt with it, but if you want to print a high quality image from AS there is a simple trick.

- Choose what format you want to print your image.
- Open an application for photo-editing or digital drawing (photoshop, corel painter).
- In the image settings type the desired format in cm or inches, set the resolution to 300ppi.
- Change the size to pixels, this is your size to use in AS.
- Render the image in AS, you will get a big file at 72ppi.
- Open the image in the external application, change the ppi to 300 (be sure that size is displayed in pixels).
- Now you have your high quality image ready for print with your desired size.

This process requires a lot of cpu/ram usage. Be careful with old systems.

Posted: Sat Dec 18, 2010 9:03 pm
by PARKER
Thanks Uolter.

Posted: Sat Jan 01, 2011 11:12 pm
by cheyne
Hi Uolter,

I'm a Graphic Designer by trade and work mostly in print.

You can't technically "add" extra DPI to an image. Well you can but you wouldn't get the same quality as say producing an image digitally at 300dpi to begin with. Typically the result is a blurry image - you are FORCING pixels/details into an image. It's like taking a thumbnail sized image, adding extra DPI and trying to print large. It just doesn't work.

To explain a little, of course you can up Photoshop or some other image editing program, go to your image properties and change the DPI but this pushes extra pixels into an image that didn't have the detail for a higher DPI in the first place. Sorry if my explanation is confusing. There are a many good explanations for DPI in regards to printing on the web and WHY you shouldn't take screen resolution images (72dpi) and force extra pixels into it for use in print.

You can "upsample" images when adding DPI but unless you were DESPERATE you wouldn't increase by such an large amount. It damages the quality of images, makes images smaller (depending on how you upsample). But to be fair, if it's not a complicated image like a photo, flat colours and vectors can turn out OK - I still don't recommend changing DPI from lower to higher.

What you really should do if you need to export a print a quality image from AS is to set the project settings pixel dimensions REALLY high. A good rule is to have the pixel dimensions at least TWICE the pixel dimensions (at a minimum) of the desired output size. E.G. An A4 sized image at 300dpi is 2480 x 3508 pixels. If you want to print an A4 image from AS, I would set your dimensions to 5960 x 7016 (minimum) and WHEN you PRINT choose from the print dialogue options "shrink the image to fit" or some similar option (Acrobat has this option when printing as PDF) (don't try to adjust in an image editing suite).

To be even more confusing, in digital terms if you have a large enough image in regards to pixels you can pretty much ignore it's DPI settings. E.G. I worked in a place where I bought lots of stock images, mostly they were set at 300dpi, BUT a lot were just VERY large images pixels wise, like 15000 x 25000 at 72dpi etc.

There's a lot know about image editing and setting up for print quality to learn, I am happy to share my knowledge - sorry I don't have time to find some more links! Hope this helps :-D

http://en.wikipedia.org/wiki/Dots_per_inch

Posted: Sun Jan 02, 2011 10:57 am
by slowtiger
If you happen to own Flash, you also could export from AS as SWF, open in Flash and export as Illustrator AI. You'll get a nice resolution-independent vector file.

Posted: Sun Jan 02, 2011 12:55 pm
by Uolter
cheyne wrote:Hi Uolter...
Thanks for your answer but to be less confusing you should verify if you're talking about ppi or dpi.
I did my searches, on the net and asking some professional friends and found that the way I described is right and commonly used. . I already did some prints (with a little of workaround with colour management). No blurry images.
Consider the following:
1)If you set the size in pixels and change the resolution, the real dimension does change increasing or decreasing quality.
2)If you set the size in inches or cm and change the resolution the real dimension doesn't change but the quality does.
In an A4 image at 300ppi you have 2480x3425 pixels, increasing or decreasing ppi will not affect the pixels, you're just providing information on how to read the image, at 300 ppi is 8.27 × 11.69 inches, at 72ppi is 34,4 x 47,5. Pixels are the same but the size is different so you have two images, one bigger with low quality and one smaller with high quality. No pixels where pushed, they're just what they are, it is the concentration that changes, providing different quality to the image.
Dpi is the printer resolution and it is another matter. For 300ppi images should be 1440 or 2880.
Thanks, anyway :wink:

Posted: Sun Jan 02, 2011 1:06 pm
by Uolter
slowtiger wrote:If you happen to own Flash, you also could export from AS as SWF, open in Flash and export as Illustrator AI. You'll get a nice resolution-independent vector file.
Thanks Slowtiger, but you have to say this way only works if your file doesn't have effects that swf export doesn't support.

Posted: Mon Jan 03, 2011 8:42 am
by cheyne
Hi Uolter,

To clarify my examples refer to DPI (I learned a lot from old books in early days, old school 8)). PPI and DPI is typically set to 300 when you setup in your image editing software of choice. So while I know what PPI is and how it works, I've always just worked with DPI when dealing with print considering they go on the same units.

What I was trying to get across in my earlier post is about why "upsampling" through adding pixels to an image with lower PPI/DPI (it doesn't matter which, it's all about the pixels) to a much higher resolution isn't a great idea. And that's why my advice was to export the images from AS at larger dimension - which has more pixels. At first it can be confusing, but just because an image isn't 300dpi/ppi or whatever, doesn't mean it can't be printed with quality - it just needs to be LARGE. Like I said about stock images I've purchased over the net, some were 13000x25000 etc. Good quality, just setup a different way.

I understand you were given some advice and while it works in regards to your process, it's not an ideal way to work in my opinion (and also technically, check out last link). I'm just finicky like that personally :)

Take a read of these two links when you get the time, no more than a minute per page. Good explanations of PPI and DPI and talking about printing in the digital world.

Nice explanation of DPI and PPI (photographer) - http://www.andrewdaceyphotography.com/articles/dpi/

Has good explanation about upsampling (adding pixels) and why it can go wrong - http://www.imagescience.com.au/kb/quest ... PI+and+DPI

Cheers mate
8)