Question about file type and printing

[Ravich]

I am relatively new to this stuff, but I understand the concept of DPI and I am told that 200 (better yet 300) is desirable for printing.


What I dont understand is how to get the file out of photoshop into a printable medium. So my question is.... why do people use PDFs? I have a volunteer designer doing post cards for a concert series, and we have them printed professionally. I have been noticing that our postcards tend to... look kind of like crap. Obviously they are passable, or we wouldnt be sending them out, but I just spent a bit of time trying to figure out why.

I noticed that the PDFs (these are 4x6'' postcards, btw) are all 441x291 resolution. So roughly 72DPI, right? Well... no wonder. So I opened up one of the photoshop files for these postcards I had lying around from last year and checked the DPI, which was 300. I tried saving it as a pdf without compression, with compression, etc.... and every single time the resolution was the same. Then I tried saving it as a TIFF. And there it was. Exact same size (8.8MB) as the PDF without compression, except the resolution is 1838x1238. 300 DPI basically (there is fudge room on the borders of the post card, hence the extra pixels).


So my question is..... why would I ever use PDF? Is TIFF not acceptable for printing? I clearly must be missing something if PDFs cant exceed 72 DPI.

 

[Apple OC]

Save your Photoshop files as High Resolution PDFs ... that is what most Professional Printers would request to print from

 

[Ravich]

That's what it's been set on (without my really knowing it), but it's still saving a PDF with 72 DPI, which, from what I understand, sucks for printing.

 

[Apple OC]

was the file started as 300 pixels per inch? ... 72 DPI is for web images

 

[Ravich]

Definitely. When I go to the Image --> Image Size box, it says the resolution is 300 pixels per inch.

 

[design-is]

Regardless of the PDF resolution issue, have you asked the printer you use if they will accept a tiff as the source file? Most printers I know would be happy to do so... Just make sure you don't save with a lossy compression.

 

[Ravich]

I am pretty sure they'd be fine with tiff files. I just really want to understand why anyone would use pdf for printing if the maximum dpi is 72.

 

[design-is]

I am pretty sure they'd be fine with tiff files. I just really want to understand why anyone would use pdf for printing if the maximum dpi is 72.

PDFs don't have a maximum dpi — they have the dpi you assign them. In photoshop, you assign the dpi of the image you're working on, and then when you save out as a PDF if you want to you can downsample using the window in my attached screenshot. The PDF will honor these settings...

Where is it telling you the dpi is so low? I've found that the finder (or cmd+i to get info) lies about the resolution. Try opening the PDF again in photoshop and looking at the image size — it should hopefully tell you it is still 300pdi at the measurements you've set.

 

[MechaSpanky]

The normal formula used to figure the correct DPI is double the line screen. If you are getting something printed using a 150 line screen, then 300 dpi or greater would be good. If you are having something printed using a 72 line screen, then 150 dpi is acceptable (or greater).

Newspapers generally print using a 72 line screen and higher quality off-set printers usually use 150 line screens (there are some that use even higher line screens) so it is important to talk to your printer before you design something (or always design it at 300 dpi). Most printers will give you a spec sheet with their recommendations for how you can best prepare your files for print if you ask them.

Are you building the entire piece in Photoshop? Are you setting all your type in Photoshop? Normally I would recommend that you don't set your type in Photoshop and instead use a dedicated layout program like Quark Xpress or InDesign (or Illustrator will do as well) to set your type. There are occasions when you want to use Photoshop to create stylized type (or if you are creating a drop shadow or something like that) but other than that, don't set type in Photoshop if you want your type to look good (unless you are setting the type as vectors in Photoshop, but most people don't do that). Best of luck.

 

[citizenzen]

Best of luck.

Once again I am baffled by people's reactions to posts.

Not MechaSpanky's. He provided good, useful information that could help the OP produce better work.

But for some reason, somebody decided to give Mecha's post a negative rating.

Why? Is helpful on-topic information now out of fashion these days? What is in the mind of some people these days? I haven't a clue ... and hope I never do.

Now, back to the topic ...

The OP says these cards are professionally printed. A good printer knows that a bad finished product doesn't reflect well on them, even when they had nothing to do with creating it, and a good professional printer will take time to explain to their client what is necessary for submitting technically correct files.

I would call the printer, discuss the issue and see what tips they can provide. I've been in the pre-press and design business for 20 years and have never hesitated to advise clients on these matters. This is a resource the OP should take advantage of.

 

[Ravich]

PDFs don't have a maximum dpi — they have the dpi you assign them. In photoshop, you assign the dpi of the image you're working on, and then when you save out as a PDF if you want to you can downsample using the window in my attached screenshot. The PDF will honor these settings...

I avoided downsampling.

is it telling you the dpi is so low? I've found that the finder (or cmd+i to get info) lies about the resolution. Try opening the PDF again in photoshop and looking at the image size — it should hopefully tell you it is still 300pdi at the measurements you've set.

Aha, you're right here. I was getting the DPI from dividing the resolution (441x297) by the dimensions in inches. That works, right? The finder was, in fact, giving me incorrect information since when I open the pdf in photoshop, it reads the resolution as much much higher and 300 dpi. Thanks for helping me clear that up.

It must have something to do with the way that out volunteer designer is saving the pdfs, in that case. Or maybe the source images arent very high DPI, which wouldnt surprise me. Still, resampling would at least prevent things from turning out dotty in the printing, right?

The reason I'm not asking the printing company is because they're basically doing us a favor via a business partnership type thing, and I'd be wasting their time getting them to try and figure out why something that isnt their fault is causing the images to be printed poorly.

Thanks for your help everyone.

 

[Ravich]

I'm just going to attach an example from one of the post cards.

 

[Designer Dale]

I'm just going to attach an example from one of the post cards.

I think something is messed up with the example you posted. I only get about 25% if it.

As for the PDF question, there are two ways to get a PDF out of PhotoShop (I use CS3, but it should be the same on any current version). One is to hit the print command on the keyboard - Command-P - and select PDF in the lower left corner. The other is to use Save As and select PhotoShop PDF. The Save As route takes you through a dialogue box to set quality output for the PDF file, the Print/PDF button dosen't. There is a difference in the file sizes of the two. Making the PDF through the Print command flattens all the layers. PhotoShop is one of the few applications that will not route you through easy access to PDF setting from the keyboard Print command.

ps I realize it is an assistant creating the PDF files.

Hope some of this helps.

Dale

 

[btbrossard]

Once again I am baffled by people's reactions to posts....

Everyone is a designer (and knows everything about prepress and printing) it seems.

I though the post was good.