Redbubble Help ??

[bigdazzler]

Ive just opened a Redbubble account and have a few images that im happy enough with to put on there for sale. Now I need to get my head around suitable resolution/pixel dimensions/dpi ..

Im a little bit stuck on the best way to prepare the images for upload.

Redbubble require files to be at least 3854 x 2560 (10mp) for large prints. They make no mention of minimum dpi. See here (http://support.redbubble.com/faqs/selling/size-format-colour) for requirements.

My Sony is a 10.2mp camera. Im pretty certain that the dpi straight from camera is 72.(Ill confirm this when I get home tonight and get my hands on my camera, but im 99% certain of it)

Most of the info Ive read seems to indicate that for the best print quality, dpi should be around 240 or 300 .. Now when Ive finished editing in GIMP and providing the resolution in pixel dimensions meets the RB requirements (as above) should I change the dpi in the "Print Size" tab from 72 to 240 or 300 before saving and subsequently uploading to RB ??

Is this the right way to prepare the file ?? and if so, will changing the dpi affect the pixel dimension of the file or is the dpi only relevant to the printing process ??

Am I on the right track here ..

[David Kembrey]

Darren prob the best place to check is the forums on red bubble or the q&a section.

[bigdazzler]

Yea it was as much a general question about resolution/dpi as it was the RB thing .. Im still trying to get a proper understanding of it ..

[ricktas]

DPI is only really relevant for printing, I make sure all my work for printing is set to 300 DPI.

Not sure how gimp works so might be worth saving a copy of your photo, and then resizing that to see if it only affects the DPI or if it changes the whole size of the photo (it shouldn't).

72-100 is a good standard PPI (pixels per inch) for display for the web.

[Dizzy Photographics]

Might have no idea but i've just been going through this with my photography teacher actually. We've all had to get a redbubble account to show our stuff between other students (our prints go on exhibition at the royal show this year) and anyways..the process i was told was before doing anything change the dpi to 300 and then change the document dimension to the 'cm' size you want the image to be...on the longest side. Dont now if that works the same for red bubble or not though

[bigdazzler]

DPI is only really relevant for printing, I make sure all my work for printing is set to 300 DPI.

Not sure how gimp works so might be worth saving a copy of your photo, and then resizing that to see if it only affects the DPI or if it changes the whole size of the photo (it shouldn't).

72-100 is a good standard PPI (pixels per inch) for display for the web.

Thanks Rick .. Just got home and did a little experiment on one of my TIFF files, exported straight from the RAW file in Aperture with no changes at all, just a simple RAW>TIFF conversion

I opened the tiff in preview - pixel size is 3872 × 2592 @ 72 dpi (file size 28.7mb)
I saved the tiff as a best quality jpg - pixel size and dpi didnt change, still 3872 x 2592 @ 72 dpi (file size 8.7mb)

I opened the same tiff file in GIMP ..
Theres two different tab options available here, "Print Size" and "Scale Image" where I can change the dpi

When I open "Print Size" with the image at the pixel dimension of 3872 x 2592, @ 72 dpi the image size in inches is 54 x 36. If I then change the dpi to 300, the height/width parameters change to 13 x 8 inches. Obviously a much smaller print size.

Is this telling me that these sizes are the biggest print I am able to make at the respective dpi without reducing/pixelating image quality ??

Next ..

When I open "Scale Image" if I change the dpi from 72 to 300, the pixel dimensions dont change .. they remain at 3872 x 2592. So it appears that changing the dpi doesnt change the actual dimensions of the image file..