POSTER
paul
am doing volunteer work to promote an event for charity.
I need to produce a color poster A3 size (420mm x 297mm) for printing.
The printing people requires a file of actual size as CMYK.
Not exactly sure at what resolution i have to work. I tried to do it all
in Photoshop but the files are too large. woudl 300dpi suffice for
printers to work with?
How can I avoid that? Can I work in a lesser resolution then enlarge
retaining quality? How do you professionals do it?
Any ideas or advice will be appreciated.
Thank you
CM
darrel
> retaining quality? How do you professionals do it?
Vector art is resolution independant. Meaning you can scale it without
worries.
Raster art (such as photographs) is resolution dependant, meaning you have
to work with it at the resoltion and size you ultimately want to print it
at.
Offset printing is typically 1200 - 2400 dpi. Raster art such as photographs
should be run at roughly 300dpi, actual size.
-Darrel
paul
> worries.
> Raster art (such as photographs) is resolution dependant, meaning you have
> to work with it at the resoltion and size you ultimately want to print it
> at.
would this apply to any images, say, created by Photoshop for example?
> Offset printing is typically 1200 - 2400 dpi. Raster art such as photographs
> should be run at roughly 300dpi, actual size.
thank you Darrel
darrel
You need to understand the difference between raster and vector artwork.
Vector artwork is made up of lines, and points. When you draw a shape or
line in Freehand, flash, or Autocad, or any other drawing-type program, you
usually are creating vector art work.
The advantages are that vectors artowork can be scales without any
resolution worries. The drawbacks are that vector artowork is really only
suitable for hard lines and solid colors (with some exceptions).
When you want to create continuos toned images (like photographs) or 'soft'
effects like drop shadows and blurs, then you need to use raster
images...which are images made up of individual pixels. These images don't
scale up, because the only way to make the image bigger is to then make the
pixel bigger...which turns your image into a jaggy, boxy mess.
Both Freehand and Photoshop can make raster and vector images, though, PS
excels at raster art, and FH excels at vector art.
-Darrel
ellipsis
>would this apply to any images, say, created by Photoshop for example?
Yes. Newer versions of Photoshop have some sort of live text and raster capabilities, but I have not experimented with them yet, and am ignorant of their parameters. All raster (commonly referred to as bitmap) images have an 'optimum' size for printing, and stretching them to fit a larger area will degrade their appearance. A Photoshop file is a raster image - even if it is exported as EPS.
>> Offset printing is typically 1200 - 2400 dpi. Raster art such as photographs
>> should be run at roughly 300dpi, actual size.
Some professionals routinely print raster images at resolutions as low as 225 pixels per inch. I have looked at Adobe Photoshop tutorial books printed at 175 lpi, and I was able to see minute differences in sharpness at image resolutions up to 300. At 350 ppi the differences were negligible, so I use 300 as my personal standard for general offset presswork. This corresponds to the 'twice the line screen' rule of thumb at a screen of 150 lines per inch.
Poster work can be run at the lower end of the ppi scale, since (generally) the larger a poster is, the greater is the expected viewing distance, and the less the human eye will perceive a loss of detail.
A poster built entirely of vectors in FreeHand can be scaled almost at will, and the output file will still be very close to the same size, and will be very small in comparison to a raster image which would print to the same print area.
It is commonplace to mix raster art into a piece being designed in FreeHand. These images need to be sized (before importing to FH) in accordance with the expected print size of the piece. They should also be converted to the CMYK color space in Photoshop, and then saved from Photoshop as either TIFF or EPS.
Because vectors are scalable, and are resolution-independent, the 'Resolution' setting in FreeHand's page inspector does not behave as one would suspect. It merely determines the number of steps that are placed by default into blends between objects, and can also affect the number of steps in gradients in artwork that is exported in the Adobe Illustrator format - neither of which is going to mean much to you. Because all of my work is in print, I set my FH 'resolution' to the maximum setting and leave it there.
So, what you need to do is set up a page in FH that is the proper size, set your resolution to the highest level, and go to work. If the printer doesn't have FreeHand, you will need to export your artwork as Quark EPS and deliver it to them in that format. Make sure that you embed the fonts (via a sub-dialog in the EPS export panel) when you export. As an alternative to embedding fonts, you can convert all of the type in your poster to paths and that way the EPS will be compatible with any output workflow. If you decide to convert to paths, make sure you do this to a COPY of the final document, so that you can go back and make any necessary edits to the 'live text' in the original.
At any rate, after mucking around with Photoshop, you will be surprised at the small file size of your poster when built in a vector program. The razor-sharpness of vectors will be apparent in the final product. Even at 300 ppi, raster images are not nearly as crisp when they get to paper.
I'm 'on the run' and trying to cover a lot of possibilities here, but I'm sure that you will have many other questions. If you do, try to post them as a reply to this thread.
Also, find out from the printer what type of file they prefer, and who is to take care of any trapping that is needed.
Good luck!
Ken Kehl
ellipsis design