I use them for my color work, but have not tried them for b&w as yet. These people will answer your questions via email.
I do all the file prep and either upload or send in a cd; they will send mailers for free. I would think that a cd would be preferable for larger files or alot of pictures, at least I have found it so.
There is an option box when you select which pictures you want printed that allows you to choose a crop for the size print and wether you wish to have them color correct the print.

Monte,

your post and one on another forum got me off my dufff to order out two prints from MPIX. files attached.

Nice Image Ronk. Good tones. Thanks for the info. I will give them a try sometime. Only if my printer quits. I love the RC prints I get right now, but as you know paper and suppies are going. So are traditional BW printing. For now I will stay where I am. I do not have the work flow problem. Monte Johnson.

I gave up my trastionalk darkroom na yr ago. I have been trying to perfect the digital technique. thanks for your input on the snaps; we will see how they print.
My regualr ink jet is just dreadful on b&w!

Ronk as you well know BW is hard to get just what you want on a home digital printer. My Epson does not do bad, but I can't quite get there. Many labs give information about the printer they use,but MPIX has no input on what they use. I am sure it is a good printing system. If you do some BW with them let ne know what you think. I have not had real good luck with other labs when it comes to digital BW prints. I know if I do send them an image to print I will send a CD instead of trying to download an image. Thanks again for your help. Monte Johnson.

Mpix emailed me that the prints were shipped last night, so they shouls be here sat or mon.

Ronk,

Looking forward to seeing how it turns out. I printed a 3200dpi scan of a BW yesterday on a large format Canon printer. It was pretty good, but not as nice as the RC prints I have. It was a 24+36 print. Monte Johnson.

the pictures came back today, friday mail.
they were exactly as I sent the file to them. the paper surface is matte, I would really prefer a lustre as close to Ilford pearl as I can get, which is as close to the OLD Zone V1 FB paper i used to use.
I think that if they can print the b&w file on the regular Kodak Endura paper, it could be a winner; as is, not really.

Ronk, Thanks for testing this out for me. I think for now I will stick to where I am at. After that runs out I do not know. Monte Johnson.

i emailed mPIX, they WILL print b&W on the E surfave paper!

Ronk,

Looking forward to your report back.