Questions about resolution?
Conventional offset printing uses dots arranged in offsetting screens to print your photos. Historically, analog screens were used with a frequency of 85 lines/inch for newspapers, and 133 lines/inch for coated paper.
With the development of digital, direct to plate technology, the frequency has gotten tighter, so that now it is much more common to print 150, 175, or even 200 lines per inch.
A good rule of thumb, is that the photo you submit for printing should have twice the line screen, in pixels per inch. (Which is where you get the often recommended 300dpi for print. (150 lines/inch screen times 2). It is important that the dpi be determined at the intended output size, and after any cropping you may need.
We can print most anything, but the quality of the output is greatly determined by the quality of the files submitted.
Digital photos are defined by pixels. The pixels on your screen are spaced at about 72 pixels/inch. While it is true, that "dots" are not the same as "pixels", 72 ppi can be thought of as 72 dpi. We like to have 300 dpi at a minimum, so you can see that it is possible to have a photo that looks good on your screen, but does not print as nicely as you would like.
Please let us know if you have questions. Our job is to make you look good!