gvarner wrote:
How much technical detail do you have to be aware of when dealing with the commercial print labs? What constraints do they put on your file size and type? How do you guide them to get the most out of your photo? Your experiences would be appreciated.
Ex pro lab guy here:
First, let's define terms a little more precisely:
A "commercial printer" is generally known as an offset lithographer, a company using huge presses and pigment inks to print books, magazines, packaging, etc. I worked for three companies that did school yearbook printing, via offset lithography. We also had professional portrait labs:
A "commercial photo lab," more commonly known as a "professional color lab," makes prints for photographers and artists. Most commonly, the process is based on silver halide chromogenic (dye based) paper developed in wet chemistry, but may also include much higher quality inkjet printing using 8-14 inks on a wide variety of papers and other substrates (canvas, metal, etc.). Pro labs typically serve a broad range of customers and clients who range from barely competent to brilliant artists. A good lab has technical service reps who can communicate across that spectrum.
A "high-end service bureau" serves artists, ad agencies, museums, and others, typically with "giclee" printing services. "Giclee" is a fancy word that really means high-end inkjet printing! The folks in this rarefied atmosphere really know their processes and materials and techniques. They are the ones that the very top photographers and museums and artists who sell limited edition prints go to — if they don't print their own work in a spare bedroom. Service bureaus typically deal with very experienced and sophisticated clientele who may have specific needs such as logo color matching, printing with UV-resistant inks on weather-resistant substrates, etc.
I'm going to assume you want a professional color lab. Most of my career was in that arena.
The #1 technical detail you need is an understanding of how to dial a telephone! Email helps, too. Getting the best results from your lab requires communications. The lab folks hate ambiguity. The more information you can give them about your files, your subject, what look you want, what finishing materials you need, and so forth, the better the results tend to be.
Most pro labs want files as full-size (large file size, fine quality, i.e.; with minimal compression) JPEGs in the sRGB ICC color space. The vast majority of them ASSUME this is what you will provide. If you want to give them a 16-bit TIFF file, ASK AHEAD, and label the files when submitting. If you want to use Adobe RGB or ProPhoto RGB as the ICC color space, ASK AHEAD, and label the files when submitting. Some labs will print them correctly, others cannot. MOST can deal with them if they know what they are getting. Labs generally do not work with raw files, since every camera uses its own custom raw format and profile.
Most pro labs use some sort of ROES system (Remote Order Entry System). This was originally a Softworks, Inc. product that connected with Kodak's DP2 lab system and let users submit work via a very friendly interface over the Internet, using their web browsers. Variations on the same theme are evolved from that concept, and most work great. You go to the lab's website, and upload your files, simultaneously ordering all the prints and services you need. Full instructions are on the sites themselves.
Very few labs have a low MAXIMUM file size limit. Nearly all will issue a warning if your file is TOO SMALL for the print size you want. Generally, it is better to submit the entire original file, and crop your work in the ROES system, so the lab does whatever re-sizing is needed. You may, of course, do all the work yourself, but the cropping and sizing is best done by the lab software, driven by ROES on your end.
COLOR MANAGEMENT is a huge area of potential contentions or misunderstandings. If you adjust your images on your computer in any post-production software (Photoshop, Lightroom Classic, Affinity Photo, Capture One, etc.), you should know that the adjustments you make are accurate, so you see unbiased representations of what the lab will print. There are international standards for that accuracy!
ICC color management is basically calibrating and profiling all the devices in an "imaging chain" so that the color you see in one place looks like the color you see in another. From your perspective as a lab customer, your job is to use a monitor that displays 100% of sRGB, or 99% or more of Adobe RGB, if they let you use that color space. That monitor must be calibrated with a hardware device known as a colorimeter or spectrophotometer, and then profiled with the calibration software that came with the hardware device. It sounds complicated, but it isn't! X-Rite and DataColor make the solutions you need.
If you calibrate and profile your monitor correctly, and use the lab's ROES correctly, you should get beautiful results. Find a pro lab near you and give them a call. They will be thrilled to help!