@ Jim.. No easy answer, for quite a few reasons unfortunately.
Beginning with Acrylic -- first off, with a genuine acrylic float mount, the imagery is "face mounted " from behind for this process to be done correctly. Discount printers, like CVS or Walgreens, do whats called direct print "on acrylic" just to use the same phrase you did. Printing ON acrylic is very bad, you lose a dramatic amount of image sharpness and details in shadow areas.
Metal prints -- again, the quality varies greatly from print lab to lab. There are soooooo many discount printers trying to get into the "metal print" game right now. You really need to investigate professional quality print labs for the best results, if that is important to you. Also, there are many different finishes available from more high end print labs. The high-gloss metal print was a fad, serious photogs have moved on. Check out "BlazingEditions" for their dye-inused onto aluminum prints if quaity matters for you.
HIgh contrast B&W looks great on metalic paper. Have you thought about doing a Silver Gelatin Print? Digital Silver Imaging does both Fiber and Resin Coated papers from digital files and the product is vastly superior to C prints and ink jet. For personal work only as it is priced at a premium.
Thanks T-S and Chicago. I see that as usual, it's not simple and there are all sorts of variations and options being offered. I guess I'd have to buy a couple small prints from FAA to see what their print vendors produce - but of course, that can change.
I know that metallic paper can look great, I have a print on the wall (by another photographer) that's really beautiful under a small LED spot. It's sharp and the color really jumps.
I'm starting to understand that 'acrylic' is really just a paper print bonded to a sheet of clear plastic, so it can 'float' on a wall. Is that right?
More or less you are right, the print is face mounted via heat to a piece of acrylic. The acrylic's from FAA are not bad for the price. In fact I have a 18x40 Chicago skline test acrylic from FAA on the wall in front of me. I know FAA keeps the price down by using 1/8 acrylic, but I wished for larger prints we could order 1/4". You're also limited to just lustre paper... I also wish they would give an option for metallic.
Some of your bigger artists like Peter Lik, Thomas Mangelsen, and Art Wolfe use Endura paper from Kodak and Fuji Pearl/FujiFlex and THAT is in a league to itself.
As far as B&W and that is pretty much what I like to do; unless its a high contrast where I think metallic and acrylic work nicely.... I would avoid these formats and go with something else. YMMV :)
@ Jim. "I'm starting to understand that 'acrylic' is really just a paper print bonded to a sheet of clear plastic, so it can 'float' on a wall. Is that right?"
--- it depends on the level of perfection and luxury delivered by the print lab. The clear material used is a specialized lightweight acrylic glass.. Plexi, or plastic as you mentioned --- is generally used by the low end print labs I mentioned above.
The acrylic glass used for your more luxurious acrylic pieces is shatterproof, and the edging is both optically clear and highly polished. (Plexi-plastics are not) In fact, the edges won't even capture reflections, they are invisible. Lumachrome is at the top of the best acrylic technology.
* Many knockoff "me-too" labs claiming they make acrylic prints do not use fine art ultraHD photo print papers! LOL, what they do is "print directly" -- exactly as it sounds, inkjet printing directly on the back side of plastic sheets! This is done more than you might think :(
If the lab does use a fine art photo print (correct method) yes, it does get bonded to the reverse side of the glass with a specialty silicone sealant infused with iridium... The tolerances and conditions in which this process is crafted is like a hospital or NASA lab. The photo print paper also cannot be any kind of paper. As Chicago mentioned above correctly, the best labs are using "Fuji Crystal Professional Archive Maxima", "Lightjet print on Fujiflex Gloss" or even "Kodak ProEndura" papers. The paper and glass is backed by a composite aluminum DiBond.
They are generally offered as "float-mounts", yes that is correct. The best quality acrylic prints feature aluminum rails, Comatex protective backing or a Roma back mounted floating frame.
@ Jim --- Exactly! It sucks that some of the terminology & descriptive names for different print mediums is so abused. The good thing tho, is you actually DO know what your getting, it just takes a little homework and visits to their websites.
I at one time (a few years back) had accumulated over 100 samples of "dye-infused" metal prints, including one place I won't mention :) I didn't send them the easiest image files to work with either.. Sunrise/sunsets with shadowy areas --- but definitely GOOD details preserved in the shadows --- I could see on fine art photo-paper prints beautifully
No kidding, out of 100+ samples, I was left with only 8 extremely high quality dye-infused pieces. Some places I even offered them a second chance to make it better :) Anyhow, you definitely need to research, reach out, and get them to provide samples using your image files.
In order for the print to be of high quality, you need to choose a smooth polished piece of metal. If there are even small irregularities on it, the picture will be spoiled. To solve this problem correctly, you need to consult a specialist.
Choosing what sheets of aluminum are used to create your prints are out of your control. You put all of your faith in the hands of the print lab. Each panel, after being cut for your print size, is coated prior to the dye-infusion process. The high-end labs (Blazing Editions, Bay, WhiteWall, NevadaArt) carefully inspect the large/raw & uncut panels upon delivery. They have the luxury of selecting the highest quality sheets, or make cuts off the sheets.
The panels that they reject that have imperfections (small irregularities, dimples etc) are then resold to the waiting arms of the secondary market. These are all of the discount metal printers you see on Google. ie: Shutterfly, Mixbook, Walgreens and Walmarts, CVS, Costco's, BJ's, and the unlimited supply of POD sites. This is the major reason why some metal print advertisers' pricing seems so cheap... they purchase seconds (misfit island)
Then, and only then, is when the images on metal get ruined :(