Hello! I sadly do not have a DSLR yet, so all of my photos are currently from a point & shoot and are, therefore, in the 4:3 aspect ratio. Since the print sizes for this ratio are not currently available thru SmugMug's catalog for Bay, I unfortunately have to resort to ordering my prints directly thru Bay instead. Here is my problem: I am attempting to order a 18 x 24 Metal Print, however, upon creating the order in Bay ROES, it states that I must submit my file in the desired size and at 300ppi. I am a bit confused by this since we are able to upload our photos to SmugMug at 72dpi and still receive prints up to 30 x 40 (for example) thru SmugMug from Bay. The image that I would like to have as a 18 x 24 Metal Print has pixels of 4608 x 3456 at 72dpi. I do not want to have to resize/resample my image and risk losing any quality. Is there anyway around this or do I really have no other choice but to resample my image to meet Bay's requirements for ordering directly through them?

Thank you in advance for any help that anybody can provide me!

Originally Posted by rachelmedina The image that I would like to have as a 18 x 24 Metal Print has pixels of 4608 x 3456 at 72dpi. I do not want to have to resize/resample my image and risk losing any quality. Is there anyway around this or do I really have no other choice but to resample my image to meet Bay's requirements for ordering directly through them?

Unfortunately no way around this. A print size specified using x by y DPI equates into a document that you’ve already figured out but don’t have. You either resample and possibly lose a great deal of quality (depending on how you do this and how large you enlarge) or you make a smaller print.

4608 x 3456 at 72ppi and 4608 x 3456 at 300ppi are the same. The key here are the number of pixels which in this case are the same: 4608 x 3456. HOW you divide that up (take 72 per inch or 300 per inch) is what determines the actual size of the print. Digital images don’t have a size other than the volume they take up in terms of disk storage. Only when you take the pixels you have and divide them up onto a print do you get a ‘size’ (for a print).

Originally Posted by arodney Unfortunately no way around this. A print size specified using x by y DPI equates into a document that you’ve already figured out but don’t have. You either resample and possibly lose a great deal of quality (depending on how you do this and how large you enlarge) or you make a smaller print. 4608 x 3456 at 72ppi and 4608 x 3456 at 300ppi are the same. The key here are the number of pixels which in this case are the same: 4608 x 3456. HOW you divide that up (take 72 per inch or 300 per inch) is what determines the actual size of the print. Digital images don’t have a size other than the volume they take up in terms of disk storage. Only when you take the pixels you have and divide them up onto a print do you get a ‘size’ (for a print).

Hi Andrew! Thank you so much for your response! Ok, I believe I understand how ppi works and how to calculate everything out in terms of pixels and print sizes. What I guess I don't understand is why we are able to upload our images onto SmugMug with a 72dpi and order (for example) a 30 x 40 print with Bay Photo through SmugMug and not have to worry about resizing/resampling anything, yet when attempting to order directly through Bay Photo, they make it a requirement to submit a file set at 300ppi. It's the same exact lab, so I don't quite understand why the terms of submitting a file differ for the two. I assume that Bay must do their own upscaling with orders from SmugMug to achieve the best possible results, so wouldn't they be able to do the same with orders placed directly through them? I mean, what's the difference? I'm confused. I did notice that they are only requiring files to be set at 300ppi for Custom Size Metal Prints, however, I still don't understand why this is necessary since, if I wanted to, I could choose a standard size 30 x 40 Metal Print from their catalog and provide them with a 72dpi file to work with which they'll accept with no problem. So why not accept a file set at 72dpi for Custom Size Metal Prints too? What's the difference? Am I missing something? I'm still a newbie to the world of printing, so I may be missing something. It's all just very confusing to me and if it's not absolutely necessary, I really don't want to have to resample my image & risk losing any quality to it if I could just leave it up to the experts like with any other order (not to mention I'm still pretty much a newbie at Photoshop too, so besides doing Image>Image Size and filling out all the necessary fields, I wouldn't know of any other way to produce the best resampled image to submit). If you have any information that can enlighten me on this subject, I'd truly appreciate it! Thank you again!

I think you misunderstand resolution. The correct term is ppi (pixels per inch) rather than dpi (dots per inch) and refers to image pixels per printed inch. Bay Photo requires 300 image pixels for each inch of your print, regardless of its size or aspect ratio. There's no getting around that requirement.

If your print is to be 18" on the short side, that requires a resolution of 18 x 300 = 5400 pixels on that side.

One alternative might be to use a print lab (like Mpix) that accepts images with lower resolution -- though I believe that their printers will automatically resample the image to 240 ppi. You could ask them about that before you put in an order.

Originally Posted by rachelmedina What I guess I don't understand is why we are able to upload our images onto SmugMug with a 72dpi and order (for example) a 30 x 40 print with Bay Photo through SmugMug and not have to worry about resizing/resampling anything, yet when attempting to order directly through Bay Photo, they make it a requirement to submit a file set at 300ppi.

I don’t use either service. I have to assume any time someone asks for 72ppi images, they are using this for screen output on the web. Not that everyone is using a 72ppi output for displays (a urban legend), it is close enough to specify an output resolution for this use. The same is true for output to a printer. Another silly urban legend is that there is some standard requirement of 300 ppi images for 300dpi output. Absolutely not true or correct. It depends on the output device. But when someone ‘demands’ 300ppi images, they are probably going to print them and they may or many not actually use 300 dots pre inch for the output device.

In the example of printing yourself with say an Epson printer, that device can produce 1440/2880 dpi but you would never send a document with 1440/2880 dpi to the printer. Not only would the document be huge, you’d actually get inferior output. This device doesn’t lay out 1440/2880 dots in a linear fashion yet saying the output is this value for resolution is correct. You’d send out anywhere from a minimum of 180 ppi to a max of about 480 ppi to this printer. In fact you’d just tell Photoshop what size print you want (13x19), and as long as the pixels work out to a value between 180/480, even if the values are odd (183, 234, 398 etc), you’d let the print driver handle the interpolation to produce the size (13x19) you asked for.

Lots of labs ask for 300ppi images. Doesn’t mean they are really producing 300 dots per inch.

Originally Posted by Peano I think you misunderstand resolution. The correct term is ppi (pixels per inch) rather than dpi (dots per inch) and refers to image pixels per printed inch. Bay Photo requires 300 image pixels for each inch of your print, regardless of its size or aspect ratio. There's no getting around that requirement. If your print is to be 18" on the short side, that requires a resolution of 18 x 300 = 5400 pixels on that side. One alternative might be to use a print lab (like Mpix) that accepts images with lower resolution -- though I believe that their printers will automatically resample the image to 240 ppi. You could ask them about that before you put in an order.

Hello! Yes, I apologize, I did interchange ppi and dpi somewhat incorrectly in my post. However, after some research, I believe I do know the difference between the two now. Thanks!

As for the lab, I'd rather not go through any other print labs (I love Bay!) so I actually reached out to Bay Photo directly to discuss the issue at hand and them being as awesome as they are, are gladly accepting my file as is with no problem to produce my 18 x 24 Metal Print. So yay! Thank you for taking the time to respond though!

Originally Posted by arodney I don’t use either service. I have to assume any time someone asks for 72ppi images, they are using this for screen output on the web. Not that everyone is using a 72ppi output for displays (a urban legend), it is close enough to specify an output resolution for this use. The same is true for output to a printer. Another silly urban legend is that there is some standard requirement of 300 ppi images for 300dpi output. Absolutely not true or correct. It depends on the output device. But when someone ‘demands’ 300ppi images, they are probably going to print them and they may or many not actually use 300 dots pre inch for the output device. In the example of printing yourself with say an Epson printer, that device can produce 1440/2880 dpi but you would never send a document with 1440/2880 dpi to the printer. Not only would the document be huge, you’d actually get inferior output. This device doesn’t lay out 1440/2880 dots in a linear fashion yet saying the output is this value for resolution is correct. You’d send out anywhere from a minimum of 180 ppi to a max of about 480 ppi to this printer. In fact you’d just tell Photoshop what size print you want (13x19), and as long as the pixels work out to a value between 180/480, even if the values are odd (183, 234, 398 etc), you’d let the print driver handle the interpolation to produce the size (13x19) you asked for. Lots of labs ask for 300ppi images. Doesn’t mean they are really producing 300 dots per inch.

Hello again Andrew! As you can see in my previous post, after much discussion with Bay Photo, the lab is gladly accepting my original file size as is to produce my 18 x 24 Metal Print. Yay!

I do want to thank you though for the wealth of knowledge that you provided to me in just the 2 posts that you wrote. I have a much better understanding now of the issues surrounding printing and ppi's. Thank you so much!