Rendering to bitmap instead of keeping vectors and fonts: noticable?

[smash]

I was wondering if there is any difference in quality when you save your finished work (an A4 flyer, for instance) as a 600 DPI TIFF image, instead of a PDF that includes vector images and the original fonts.

I have been supplying our digital press service (who print on a HP Indigo and an Océ printer) with TIFF images because I can only use Photoshop at work, but I wonder if fonts etc. will look less fuzzy if I supply a pre-press compatible high quality PDF (like I do for offset work). Anyone have experience with this?

 

[Sherbert]

Yes, the quality of the fonts will be better if they aren't pre-rasterised.

Your printer will most likely prefer a Photoshop PDF (which will keep fonts as vector) over a rasterised TIFF.
Just make sure you don't use faux fonts.

 

[Wolfie]

Rasterizing text always leads to problems, if the file is going to be printed at 1200dpi then you need your tiff as 1200dpi, which can lead to a very large file size and longer processing time on the rip.

The text will look different than the unrasterized version, they always seem bolder, just slightly.
But my main worry is the prepress guy wont have any control over trapping and if using icc profiles they may not be able to keep the black text as 100% black.

 

[smash]

So theoretically (not taking into account how unpractical or slow it would become) the differences between a 1200 rasterised TIFF and a PDF containing embedded fonts and vector artwork would be unnoticable?

I'm not trying to encourage this way of working, I am just interested in how the differenced come to be. I'm trying to get a mental model in my head of how the digital printer/press would output nicer letters if it has access to the vector data of the fonts. In the end it prints the same amount of dots per inch on paper, wether it's a photograph or black text, right?

 

[Sherbert]

The RIP will do a better job of converting vector text into raster than photoshop will ever be able to.

 

[Wolfie]

Yes it would be unnoticeable, as I said the only slight visual difference is a slightly bolder type, you would only notice if you had a side by side comparison. That's once your tiff is the same dpi as the output resolution.

Just remember, what ever the workflow, in the end it's a high res 1-bit tiff going to a platesetter, which in essence is what your doing, but instead of 2400/2540 dpi your going 1200dpi.

 

[smash]

Thanks again guys, this cleared up a lot for me!

 

[X33]

A flattened PDF at 300dpi is pretty much the standard in digital printing. Anything at a higher resolution will increase significantly processing speed and better quality will not be noticeable.

There's some literature about this that you can get :

Graphic Design Services for Graphic Design Agencies : Xerox

 

[Lukas Engqvist]

A flattened PDF at 300dpi is pretty much the standard in digital printing. Anything at a higher resolution will increase significantly processing speed and better quality will not be noticeable.

There's some literature about this that you can get :

Graphic Design Services for Graphic Design Agencies : Xerox

Oh? I'd notie but you're surely not talking about black text are you? Or line art technical drawings?

 

[Wolfie]

Yeah for contone images, 300dpi is ideal, but for vector that has to be rasterised I'd use what ever resolution you're printing it at. 300dpi will give rough edges on text.

 

[mattbeals]

If you have to rasterize a PDF, or create a page in PhotoShop and save as a PDF, you need to be careful of creating rich blacks and three/four color grays. Images are usually preferred at 300 dpi. But if you do that in PhotoShop then the text also becomes 300 dpi. Which for text is soooooo 1980's. If I recall correctly PhotoShop can save type as live/vector objects. That would be best if you have to go the PhotoShop route. But your service provider needs to be able to process that correctly. If you rasterize/create the PDF at 600 dpi then you've got way over-res'ed images to get smooth text and line art. If you're able to create everything, or as much as possible, as vector objects (try using Scribus if you don't have InDesign) then text and line art will always print at the highest resolution available on the RIP (or the resolution the provider uses).

So if you can make a PDF using InDesign/Illustrator/Scribus/etc then you can use Acrobat Professional to preflight the document to make sure it's all correct. If you don't have Acrobat Pro you can use Callas pdfToolbox 4 to preflight the document and fix things in the PDF without the need for Acrobat.