Printing on Aluminum
Apr 28, 2016 19:47:53 #
I was asked by another Hogger to expound on a comment I made about getting some prints done to aluminum - these were some close-up shots I took of some flowers recently (I've attached a couple of others to this post as well just for yuks). So, at the risk of boring those who know all this:
Printing to aluminum is a dye sublimation process - this is not printing with drops of ink using an inkjet printer but rather printing special dyes to a transfer paper which is then placed on a specific substrate and heated; the heat turns the solid dye directly to gas without a liquid phase (which is physics is called "sublimation") and the gas effuses into the substrate. Since the gasses blend almost on a molecular level, it's kind of like having a "resolution" of millions of dpi rather than 1440 or whatever. (Besides, inkjet printers have true resolutions of 360 or 720 dpi; the 1440/2880 nonsense relates to the picoliter size droplets of ink it "spits" at the paper, but the print head doesn't move that finely.)
Anyway, dye sub prints in general look more like analog images -the shading and tonal blends are extremely pleasant. Meanwhile, the aluminum backing is superior to paper on two counts: first, it is absolutely flat and second, it has higher reflectivity than any paper can. The result is that colors can really "pop" off the print. Thus, with the right subject matter, a wall-hanging print in poster size can be pretty impressive looking. At least IMHO.
I have tried various labs (including Bay and Miller) but have found a smaller lab in northern California, Laserlight Labs, to do the best work. Their URL is http://laserlightprints.com - I don't work for them but am merely a very satisfied customer. I have sold a number of flower prints in 24x36 and 30x45 size, and am told they always get comments. Hopefully, positive ones...
While it may seem the cost of a print on aluminum is higher than to paper or canvas, know that there is no need for matting or framing with aluminum prints; in the end, it can almost be a wash. As for fading - a historical bugaboo with dye sub printing - I haven't had any issues with these prints in the 6+ years I've been doing it. A few years back, as an experiment, I also covered half of a sample print with cardboard and left it in my backyard (in southern CA) for a few weeks, and there was no fading apparent at all.
Of course, to each his (or her) own, and bear in mind that the subject matter will make a difference (probably not the printing method to use for that portrait of grandma...unless it's rendered in black & white) but my work does seem to get attention when printed this way.
I hope that helps
Printing to aluminum is a dye sublimation process - this is not printing with drops of ink using an inkjet printer but rather printing special dyes to a transfer paper which is then placed on a specific substrate and heated; the heat turns the solid dye directly to gas without a liquid phase (which is physics is called "sublimation") and the gas effuses into the substrate. Since the gasses blend almost on a molecular level, it's kind of like having a "resolution" of millions of dpi rather than 1440 or whatever. (Besides, inkjet printers have true resolutions of 360 or 720 dpi; the 1440/2880 nonsense relates to the picoliter size droplets of ink it "spits" at the paper, but the print head doesn't move that finely.)
Anyway, dye sub prints in general look more like analog images -the shading and tonal blends are extremely pleasant. Meanwhile, the aluminum backing is superior to paper on two counts: first, it is absolutely flat and second, it has higher reflectivity than any paper can. The result is that colors can really "pop" off the print. Thus, with the right subject matter, a wall-hanging print in poster size can be pretty impressive looking. At least IMHO.
I have tried various labs (including Bay and Miller) but have found a smaller lab in northern California, Laserlight Labs, to do the best work. Their URL is http://laserlightprints.com - I don't work for them but am merely a very satisfied customer. I have sold a number of flower prints in 24x36 and 30x45 size, and am told they always get comments. Hopefully, positive ones...
While it may seem the cost of a print on aluminum is higher than to paper or canvas, know that there is no need for matting or framing with aluminum prints; in the end, it can almost be a wash. As for fading - a historical bugaboo with dye sub printing - I haven't had any issues with these prints in the 6+ years I've been doing it. A few years back, as an experiment, I also covered half of a sample print with cardboard and left it in my backyard (in southern CA) for a few weeks, and there was no fading apparent at all.
Of course, to each his (or her) own, and bear in mind that the subject matter will make a difference (probably not the printing method to use for that portrait of grandma...unless it's rendered in black & white) but my work does seem to get attention when printed this way.
I hope that helps
Apr 29, 2016 11:12:39 #
OldNotMold
Loc: Just North of
First, let me say that your images are great! I'm sure that they look even better on the metal substrate. I hope that you are ok with my following comments on the so-called Dye Sub process. This mis-information has been passed around for a couple of decades. I hope this explanation/clarification is received in the spirit in which it is given.
In Dye "sublimation", the connotation of sublimation is a misnomer. The dye does not change phase from solid to gas (a sublimation process). Rather the transfer process requires physical contact between the donor film (which contains the dye dissolved in a polymer layer) and a receiver layer (typically another polymer layer into which the dye dissolves). The dye diffuses from one layer to the other, a simple concentration-dependent diffusion process. No phase change occurs.
Diffusion from the donor to receiver layer is driven by the dye concentration difference, high in the donor and low (i.e.zero) in the receiver layer. If one were to do this at room temperature, it would take an uncomfortably long, long time. The "real time" driving force for the diffusion process is heat that is applied via heating elements to the back side of the donor film. There may be several hundred individually addressable heating elements per inch of the heating head, typically 300/inch. So it is very analogous to the dpi concept in ink jet of which we may be more familiar with. The print head that spans the width of the printing device contains perhaps 2400 of these individually addressable resistive heating elements in an 8inch width, for example. The head does not move like an ink jet print head. Once a line of dots has been printed, the transport rollers advance the donor-receiver layers a bit, and the next line of dots are printed in the image dependent way of course.
The "amount" of heat applied to an individual heating element during a single event is determined by the number of pulses of energy delivered. More pulses in the event (an instantaneous event) gives more heat. More heat drives more dye to diffuse thereby giving more image density in that "dot". The fewer number of pulses, the less heat...well you get the idea. In conventional Dye "Sub" prints, there are at least 3 donor layers, that is cyan magenta, and yellow, from which dye is sequentially transferred to the receiving layer to make the image. So the receiver layer is printed 3 times in this example, once for each of the colors. The printer "backs up" the receiver layer so that the next donor color (C, M, or Y) can be printed in image wise/registered fashion.
I don't know details of the transfer of the receiver layer that now contains the image to the aluminum substrate, but I would guess that it is a heat-assisted lamination process, not at all sure about that part of generating the final print but a reasonable guess perhaps. (This would imply,of course, that the image is mirror-image printed so that it is right-reading once transferred to the metal). It is also possible that a UV and physical-handling protective layer would be laminated (or sprayed...less likely) over the whole image as a final step.
There must be a receiving polymer layer to hold the molecularly dissolved dye. Organic dyes are obviously not soluble in aluminum. If the dye were deposited on the metal surface directly, the dye would be very a dull and muddy looking powder, not to mention easily removed by wiping.
I hope this helps to understand this process. It is meant to clarify, not to detract in any way from the discussion about metal prints and their use in presenting an image. Quite obviously they have a good place in photographic presentation.
In Dye "sublimation", the connotation of sublimation is a misnomer. The dye does not change phase from solid to gas (a sublimation process). Rather the transfer process requires physical contact between the donor film (which contains the dye dissolved in a polymer layer) and a receiver layer (typically another polymer layer into which the dye dissolves). The dye diffuses from one layer to the other, a simple concentration-dependent diffusion process. No phase change occurs.
Diffusion from the donor to receiver layer is driven by the dye concentration difference, high in the donor and low (i.e.zero) in the receiver layer. If one were to do this at room temperature, it would take an uncomfortably long, long time. The "real time" driving force for the diffusion process is heat that is applied via heating elements to the back side of the donor film. There may be several hundred individually addressable heating elements per inch of the heating head, typically 300/inch. So it is very analogous to the dpi concept in ink jet of which we may be more familiar with. The print head that spans the width of the printing device contains perhaps 2400 of these individually addressable resistive heating elements in an 8inch width, for example. The head does not move like an ink jet print head. Once a line of dots has been printed, the transport rollers advance the donor-receiver layers a bit, and the next line of dots are printed in the image dependent way of course.
The "amount" of heat applied to an individual heating element during a single event is determined by the number of pulses of energy delivered. More pulses in the event (an instantaneous event) gives more heat. More heat drives more dye to diffuse thereby giving more image density in that "dot". The fewer number of pulses, the less heat...well you get the idea. In conventional Dye "Sub" prints, there are at least 3 donor layers, that is cyan magenta, and yellow, from which dye is sequentially transferred to the receiving layer to make the image. So the receiver layer is printed 3 times in this example, once for each of the colors. The printer "backs up" the receiver layer so that the next donor color (C, M, or Y) can be printed in image wise/registered fashion.
I don't know details of the transfer of the receiver layer that now contains the image to the aluminum substrate, but I would guess that it is a heat-assisted lamination process, not at all sure about that part of generating the final print but a reasonable guess perhaps. (This would imply,of course, that the image is mirror-image printed so that it is right-reading once transferred to the metal). It is also possible that a UV and physical-handling protective layer would be laminated (or sprayed...less likely) over the whole image as a final step.
There must be a receiving polymer layer to hold the molecularly dissolved dye. Organic dyes are obviously not soluble in aluminum. If the dye were deposited on the metal surface directly, the dye would be very a dull and muddy looking powder, not to mention easily removed by wiping.
I hope this helps to understand this process. It is meant to clarify, not to detract in any way from the discussion about metal prints and their use in presenting an image. Quite obviously they have a good place in photographic presentation.
Apr 29, 2016 11:19:08 #
I love aluminum prints and do them for some of my pieces. I do find the price point sort of a quibble. Most customers aren't comparing the price to a print they would frame, but to a canvas print which they do not frame. The cost is double, therefore the price is about double.
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