What's the perfect resolution for a larger poster print?

[graphic24]

On the occassion of "Natonal Mourning Day", I need to print 50, 000 larger posters. But I need to know about the the perfect resolution for a larger poster.

 

[alex242]

1:1 72 DPI, but depends of the image's quality.

 

[Ahmed Samy Nagada]

72 DPI is more than enough

 

[burgmurk]

some people think an A3 is large...
i'd agree 72dpi is 'enough' if the poster is A1 or bigger. i'd say minimum was 150dpi if it's smaller than a1.
'perfect' resolution? 600dpi

 

[Baz]

If it's just an image 72 dpi is good enough.
If it has text then my preference is 125dpi.

 

[Joe House]

I don't know about perfect, but I've always recommended 100 - 150 dpi at full size and you'll usually be satisfied with the output. (All bets are off though if you're printing for a bunch of picky printer operators with loupes in their pockets )

 

[Jburns]

Doesn't the viewing distance matter?

 

[Joe House]

Doesn't the viewing distance matter?

I think that "Posters" tends to indicate a 5' plus viewing distance. You are correct though, if this were for a POP display at a cash register with a 1 foot viewing distance, you'd want to bump it up somewhat.

 

[shoresigns]

Doesn't the viewing distance matter?

Bingo. You can't determine the perfect resolution for a print unless you know the viewing distance. Here's the formula:

resolution (ppi) = 600 / viewing distance (feet)

So based on the size of the posters and the place where they'll be hung, estimate how far back people will normally stand to look at the posters. Say you come up with 12 feet, plug that into the formula and your resolution needs to be 600 / 12 feet = 50 ppi.

 

[Solventinkjet]

1:1 72dpi for images and don't rasterize vector art or text. Badabing bada boom. As for viewing distance, as long as you don't rasterize your vector art/text and your images are 1:1 it doesn't matter. If anything you would downsample some of your higher resolution images to lower file size and RIP faster.

 

[DesireeM]

Is the artwork all vector or are there raster elements? You can only go as high for resolution as your highest resolution original raster element. So if you have a stock photo original at 600 dpi and the rest of the layout is vector I'd go as high as I could(in this case 600dpi) - assuming only a couple feet or less viewing distance. But if your raster element is only 72 dpi to begin with, then 600dpi will just "blurr" the missing pixels.

Even if everything is vector to begin with I would just go with 600dpi because it's better to have too may pixels than not enough. If you're not wasting too much time in file-saving or ripping/loading then I'd say go big.

 

[myront]

1:1 72dpi for images and don't rasterize vector art or text....

Exactly. That's why you want to use pdf. Vectors are preserved.
I'd like to add another point here. Let your RIP do the resampling. i.e. No need to resample your images in your working file. Just do the layout with whatever image was given. Unless the image is of poor quality to begin with. If that's the case find something comparable or ask for a better one. Resampling and then trying to do your layout will make for HUGE files and bog your system down tremendously. Too many times I 've seen designers resample a 72dpi image straight from a decent digital camera and then take it into photoshop and create a tiff at 5ft &150dpi then proceed with their layout and bitch because it takes too long to do anything.

 

[Bly]

150dpi

 

[KeithMan]

Why would you even consider running this on an inkjet? Offset would be the way to go for that quantity.