Selling pictues online? What PPI/DPI?

Discussion in 'Digital Photography' started by alexxk, Jul 16, 2015.

  1. alexxk, Jul 16, 2015
    Last edited: Jul 16, 2015

    alexxk macrumors 6502

    Jul 29, 2010
    Hello all,

    I'm building a web site and I have the intention of selling some of my landscapes.

    Now.. I know that images for web viewing the PPI or DPI meas nothing, but If I'm selling a photo and the "person" buying wants to print and frame.. then wouldn't the PPI I saved the image at matter?

    If I save an image at 72PPI, wont the image tell the printer to print at 72DPI? In this case wouldn't the image be bad in quality instead of saving the image at 300dpi?

    I'm confused about this part, at what Resolution to sell at?

    If I want to send an image to print at ProDPI for example they request images at 300PPI, but a person buying my images might not know about this and If I saved in 72PPI that person might not know what to do..

    Am I missing something?
  2. dwig macrumors 6502

    Jan 4, 2015
    Key West FL
    Probably, but not always.

    Applications that place the image on a virtual page and then print will generally respect the PPI embedded in the image. A 1200x1800 pixel image spec'd at 300ppi would print as a 4"x6" image, and if spec'd at 150ppi, the same image would print as an 8"x12" image in such a program. Other programs ignore the image PPI and simply fit the image to whatever page size the user has chosen.

    In general, it is best to spec the images at 300ppi and indicate the intended print size associated with the image, but there is no way to prevent the user from printing at a different size with whatever resulting image change occurs.
  3. swordio777, Jul 17, 2015
    Last edited: Jul 17, 2015

    swordio777 macrumors 6502

    Apr 3, 2013
    Scotland, UK
    No, it won't matter. What matters is that the resolution is high enough that the customer can print it at the appropriate size. For example, a 6MP image is 3000px X 2000px. Regardless of whether the metadata tag says 72 or 300, that resolution will not change.

    Not with modern printers. Historically, you used to have to tell your input hardware (a scanner) how many lines to scan (both horizontally, and vertically to give you 'dots') per inch to determine the size and detail of the digital file you created. You then had to tell your printer how many dots per inch to output - by making the input and output values different you could increase or reduce the size of the output image. But this was in the days of professional scanner operators and printers.

    These days, where printers are used by everyone (not just professionals), software does all the necessary math for you. If you tell the computer what size you want the output image, it will work out the necessary DPI to match the resolution of the file to the desired print size.

    The DPI metadata tag found in digital photographs is pretty much irrelevant these days, and unfortunately, it causes a lot of confusion for photographers. The only time the DPI metadata tag will make any difference is when you open it in a programme such as Adobe InDesign because it will place the image on a page which has it's own DPI setting. If you're just printing it and not using it in some kind of publication design software then it won't matter.

    Hopefully, your print supplier is not actually referring to the metadata tag. If they say they need images at 300DPI then that *should* just mean that they need the resolution of the image to be 300pixels for every inch you want to print. So if you want a 12x8 print, the resolution of your digital file would need to be at least 3600px X 2400px (and the tag won't matter at all).
    However, if they are seriously telling you that they cannot print a file because the tag says 72dpi, but that it will print perfectly simply by changing the tag (without changing the image's actual resolution) then they do not have a clue what they're doing and it's time to find yourself a new print supplier.

    At the end of the day, 300DPI is largely a myth. The only thing that matters is that your image has enough resolution that when you print it, you do not see individual pixels. The larger the print, the lower the DPI you need to use, because the viewer will get closer to a small print than they will a large one. For example, huge billboards obviously aren't printed at 300DPI - most probably aren't even printed at 1DPI.

    Having said all that, there is absolutely no harm in changing the metadata tag in your image to read 300DPI. It makes no difference to the image, but might help keep people happy.

    Alternatively, seriously consider using a service such as SmugMug to sell physical prints instead of digital files. That way the customer will get exactly the print they want delivered to their door without having to worry about resolution / DPI / etc. Other companies will offer a similar service.

    Sorry for such a long response, but I really hope this information helps you understand the difference between the DPI tag and actual DPI.

    Best of luck with your business venture!
  4. alexxk thread starter macrumors 6502

    Jul 29, 2010
    That was an awesome explanation.. thanks so much for taking the time and yes, I'm also considering the physical print choice by SmugMug.. but then there is another issue in which I will need to take time to research which is charging taxes and dealing with all that IRS stuff.. I know nothing about it. All I know is how to file my own as an employee from my current job. LoL

    Thanks again..
  5. swordio777 macrumors 6502

    Apr 3, 2013
    Scotland, UK
    No probs at all - Glad to be of help.
  6. filmbufs macrumors 6502


    Sep 8, 2012
    Good advice so far.
    DPI. Will your customer order an image off your website and then, either you or a third party, ships the print to them? If that's the case, your online image can be 72dpi and the image file you send to the printer can be 300dpi. If, however, you want a customer to order an image from your site and then have them responsible for printing it...well, I wouldn't recommend that for a variety of reasons.

    Framing. Oooh, that subject is a monster. Things to think about: what kind of framing styles will you offer; wood or plastic vs the final cost your customer is willing to pay; who will do the actual framing; with or without a matt; glass or plexi; how to properly pack the frame; dust between glass/plexi and image; the tools needed and finally, shipping costs. We found it easier to let the customers frame the prints. :)

    Taxes. Doing the tax side of things bites. Essentially, a good shopping cart (there's another monster of a subject) will allow you to input tax information. You will need to include every single county within your state, each with their own tax rate if applicable. That's a chore and you'll need to keep it updated each year.

    Remember this recipe: Quality + Fair Prices + Excellent Customer Service = Success. Don't skimp on either and you can't go wrong.

    Good luck to you!
  7. TheDrift- macrumors 6502a


    Mar 8, 2010
    I use a plugin from FineArt America its not free you have to be a premium member it pretty reasonable tho. It is very easy to use, just drop the widget in your site, and instant store, and customers have a wealth of size/framing options etc.. if you want to have a look
  8. alexxk thread starter macrumors 6502

    Jul 29, 2010
    Do they take care of the taxes as well?

    Its looks really nice..
  9. TheDrift- macrumors 6502a


    Mar 8, 2010

    My understanding is they sort the shipping and taxes EG. VAT, and you need to declare and pay tax on the income you receive...Fortunately my wife is a charted accountant and I tend to let her look after this area for me! :)

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