What resolution for postcard-sized prints?

[Naboo32]

Not sure if this is the right place for this question, but ...

I put some images onto a CD ROM and went and got them printed by one of those DIY processing machines in the local photo shop. As they were only going to be postcard size, I took along some 1000x750 pixel versions (which I just happened to have handy) and got them printed off.

The results don't look "pixelated" in any way, but they do look a bit "blobby", as if the ink had bled a bit.

So, I was just wondering if there is an "ideal" resolution to submit to these machines for processing at that size (appx. 6"x4")?

I've never owned a printer myself and so am a bit clueless about these things. Thanks in advance for any help .

 

[tdodd]

The "standard" pixel density for high quality printing is usually around 300 PPI (pixels per inch) so to print a 6x4 postcard you would ideally need 1800x1200 pixels in your image file.

If your files are currently 1000x750 that means they are on 4:3 format (like from a point and shoot) rather than 3:2 (like from a DSLR) and thus will not fit precisely to a 6x4 format. You will need to change your cropping to match the paper size/shape you wish to print to.

 

[Naboo32]

The "standard" pixel density for high quality printing is usually around 300 PPI (pixels per inch) so to print a 6x4 postcard you would ideally need 1800x1200 pixels in your image file.

Thanks Todd , I knew that there would be a formula for this somewhere .

I think that I might try getting some higher res versions printed and see if there's much difference. At 50p a shot, I should probably take more care over these things .