File sizes in photoshop - can anyone help me?

[porterlizz]

Hi there. I've just got my first large scale freelance project. Everything else that I have done in the past has been A3 or smaller, but I have just been asked to do some posters in A1 or A0 size.

I'm currently designing the posters on photoshop but have noticed that the file size is getting huge. I am typesetting it in A3 size. Is this necessary or as an eps will a design in A4 size be sufficient for an external printer to get a top quality picture from?

Also, in general, what resolution graphics do you use for a similar scale printing job?

Is there anyone out there who has done a similar project and if so, what file size did you go up to. I'm quite conscious of the fact that I don't want to lose quality, but I don't want the file to be too big.

I'd really appreciate it if someone could give a new freelancer some guidance on this one

Cheers

[DaveyBoy]

even if its an EPS file, for a postscript printer, it still needs to be in 300dpi at least, which is what causes the file size to rocket. For A1 and A0 prints, do the poster as an A3 eps file. Any smaller, even with postscript processing, you're going to see pixelation. This is all from experience, I never did print anything A0 but on A1, an A3 eps file printed perfectly on a designjet 5000.

File size for an EPS in A3 would generally be upto 250mb I guess. It shouldn't be that much of a problem though, transporting the EPS file on CD-Rs is easy enough.

The only thing is, you need an amazing machine to process a 250mb EPS in less than an hour or so.

[porterlizz]

Thanks for the speedy reply. I was going by my gut instinct.. which turns out to be more or less right.. the only thing was that I was doing differently was using 600dpi graphics... in the thought that at least I can reduce it if necessary - but the file was HUGE.

I will change it to 300dpi... so when would you use higher dpi... just for really large scale stuff?

I also don't need to worry too much about the size just yet then.. I'm just over 500mb. It's not going to be printed by me.. I'm handing it over to some professional printer to do.

Cheers mate

[DaveyBoy]

i've never had to use 600dpi for anything mate, 300 should be fine for these posters you're doing, especially if its mainly vector-based. Are there many photos on it? Are you having to enlarge the photos to fit the A3 page or not? Stuff like that u gotta think about, cos once you start making a photo bigger than its original size, you're gonna notice a distinct lack of quality in it. All of the vector info (ie. text and shapes) in the EPS file will scale a lot better though.

[porterlizz]

There's not too much in the way of photos... at least not in the first design I'm doing. They wont be more than about 30 cms wide at the very most. It's mostly vector.

This is so interesting sussing out how to do things differently. My day to day job involves doing in-house stuff at maximum A3 and no-one really notices if stuff is slightly fuzzy... but doing this for people who are paying to get a decent job is scarey but fun.

[DaveyBoy]

yeah i totally agree, just make sure you remember what u did when you make something that turns out really good, then you will know in future!