Replicating alu skins in graphic programmes

Discussion in 'Gallery & Designs' started by Leif Oh, Jul 10, 2005.

  1. Leif Oh

    Leif Oh Member

    When something comes your way in such a nice way as the Modelik Jak-23 "Flora" came to me (second prize in Rob's aircraft competition), it is an extra pleasure thinking about and planning for what you'd like to do with. (Leaving well enough alone is, of course, out of the question.) I hope to be able, eventually, to show several nice modifications I'm having great fun thinking about.

    First one out may be of more general interest. It has to do with accomplishing an alu-like finish on bare-metal aircrafts. If what follows works out, it will be of interest both for those building models from kits with flat grey offered as a poor substitute for an alu finish, and for those - like me - who scan their models and thus loose that very nice alu finish provided in more advanced kits nowadays.

    So here we go on another lengthy tale of:

    1. Attempting to get the alu finish more right

    The Modelik Jak-23 comes with a very nice shimmering alu print, common nowadays. Unfortunately that is completely lost in scanning. Here's what the sheets typically look like when run through the scanner:


    A thoroughly disappointing uniform grey, wouldn't you agree? Compare this with what the original aircraft looked like (here in Chech markings, as opposed to the Polish markings modeled in the kit):


    If you take a close look at this, or other photos of bare-metal aircrafts, you notice a number of things:

    1) Aluminium shows up as a spectrum of faint colours, mainly blue and tan, depending on weather and surrounding terrain.

    2) Almost every panel and section displays a more or less separate spectrum.

    We shall attempt to accomplish this by using the gradient tool. I first discovered that tool when recolouring the Storch, but only used it in passing, making the transitions between green top sides and grey bottom sides of wings and fuselage. Here the gradient tool will come into full play. We shall also try to do something about the rather flat modeling of panels, rivets, hatches, etc., using the techniques learned when recolouring the Storch.

    But first, let us get thoroughly acquainted with the gradient tool of Photoshop (or similar graphic programmes, I imagine):


    Here, I've brought up the gradient tool, and clicked in its little window to get the full menu of available preset options (there are many more in the programme library). Among the preset mixtures, I've selected one called "Chrome", which contains several of the colours we want, namely blue, two different shades of tan, plus white. You see the buckets at the bottom of the spectrum.

    This is a little bit too complicated to work with for me, so I got rid of the darkest nuance of tan, added a bucket of blue also at the far right end, and interspersed the three buckets of blue an tan with two additional buckets of white.

    You get rid of buckets by just dragging them away, and order up new ones by clicking immediately under the spectrum. If you click in a bucket you get an eyedropper sampler tool which you can use to sample for example blue at the far left end to fill the bucket at the far right end. The buckets were placed evenly across the spectrum at 25, 50, and 75 percent. Try it out, it really is much easier than I ever expected:


    After creating this simple spectrum I called it "Alu" and pressed "New" to save it as a new addition to the standard library of gradients offered. So let's try out this gradient to see what it might be worth.

    The two parts selected for this test sheet are eminently suitable, because the cut line between the two parts of the kit is not really there in the original aircraft. Therefore, we would like to hide that as much as possible. The first thing to be remembered, of course, is to cut away both cutting lines completely when building to get rid of the dark edge, and edgecolour with a suitable light grey colour.

    In addition, there are a few things we can do at this recolouring stage, namely to let the gradients that are going to simulate aluminium follow the original panel lines, across the cut lines of the kit. Use your polygonal lasso tool to outline one such panel, across the two parts of the kit, and then drag the gradient tool more or less horizontally across it:


    Here I've done the gradient for one part, and outlined a second in preparation. The gradient looks really intimidating right now, doesn't it? But not to worry, we'll soon fix that.

    Gradients are drawn in a separate "Gradient" layer, above the "Parts" layer. Therefore, it is an easy matter to adjust the opacity of that gradient layer:


    Here, I have adjusted the opacity of the gradient layer to just 10 percent. Looks much better already, right? There are three very nice features of this:

    1) You preserve the scanned original underneath intact.
    2) You can experiment with different shadings of the gradient, now or later.
    3) Every subsequent grading you draw in this layer will automatically be reduced to 10 percent opacity (while retaining full options to make it deeper in colour).

    Treating all other panels the same way, we arrive at something like this:


    Note here, that you can draw the gradient a bit differently for each panel. You can change the angle slightly, or you can end it a bit outside the selection to get a different spectrum. Experiment! The objective is to make each panel look slightly, but almost undetectably, different from the others.

    Also, be sure to treat at least the larger hatches as panels, and give them their separate gradients.

    Should we be satisfied with this? I don't think so. What we have done now is to make the dull grey surface much more lively, but it is also slightly darker, since we have added a layer of gradients. To remedy this, go down to your parts layer, and reduce the opacity there. This will make the parts layer much lighter, since there is a layer of background white below it:


    Here, I have reduced the opacity of the parts layer to 75 percent. I also renamed the layer to "Parts 075", since in other sheets there may be parts we do not wish to make paler. These have to be separated out into a layer, "Parts 100", where their full opacity is retained.

    I am pretty happy for now with how this looks. But note also, that we have created some problems. The opacity of the markings, "10" in this case, has been unacceptably reduced.

    We will fix that in the next installment. Then we will also try to do something about the hatches and rivets, which deserve to look much better that they do at present.

    Best for now, Leif
  2. bfam4t6

    bfam4t6 Member

    Wow! You have far more patients than I. The idea is a great one though. So far the alu effect is looking great, and I look forward to seeing the entire model built (1/16 scale?) with brand new rivets and all. Good luck!
  3. Gil

    Gil Active Member


    Exceedingly good work! You're discovering more and more of Photoshops capabilities for us all.

    Have you given any thought to the idea of using a texture map overlay along with the Gradient Tool? This involves using a Cloud Render, Gausian Noise, Motion Blur followed by Gausian Blur to obtain a passable looking aluminum panel. Thought was to overlay it as a mask fill option adjusting the opacity till it looks about right. Just a thought to give the panels that added extra depth cue that's really important when you don't have real aluminum to print with.

  4. Leif Oh

    Leif Oh Member

    Dustin, it really takes surprisingly little patience, you should try it. The thing is, you don't have to trace the panels that perfect (since the opacity of the gradients are reduced to just 10 percent or thereabouts, and there is always the original at full, or almost full, opacity below).

    And, as always, it takes about ten times longer to describe this thing than to actually do it. Go try it out; it may really be worth your while.

    Gil, if only I knew what patterns and texture maps are about! I've seen that the options are there, but can't get head or tail of how to begin. Could you possibly show me, and others, what it is about?

    I have just uploaded a high-resolution Alutest.jpg file (1.3 MB) of the basic (unaltered) test sheet I am working on in this thread. If anybody wants to join in, with your own programme and ideas, I for one would be very happy.

    Eagerly waiting, Leif
  5. Leif Oh

    Leif Oh Member

    Amending markings, hatches, and rivets

    In my first posting I forgot to mention that even if it is not strictly necessary to clean up the gradients that end up outside or between parts (as when we applied a gradient to an original panel that was divided up between two adjacent parts in the kit), it is very easy to do so.

    It takes three clicks: One, with the magic wand in the empty areas of the parts layer; two, for making the gradient layer active; and three for deleting the selection of empty space in that layer.

    I had already done that in the last two screenshots. Now, let's continue where we left off:

    2. Amending the markings

    Use the polygonal (or magnetic) lasso tool to outline the numbers "10". Press caps for adding to your selection (another figure) and alt for subtracting from the selection (middle of the "0").

    Now temporarily increase the opacity in the "Parts 075" layer to 100 percent, copy in that layer, and paste (the result should end up exactly superimposed in a new layer above). Call the resulting new layer "Markings". Retain 100 percent opacity for that layer, and reduce the opacity back to 75 percent in your "Parts 075" layer.


    Note that the markings layer is beneath the gradients layer, which is rather nice. Adds a bit of life also to the markings, which now otherwise stand out in full clarity. Also note that we have not changed the original parts layer one iota (apart from changing the opacity, which is easily restored, should it be necessary, like just now).

    3. Amending the hatches

    Outline one of the hatches with the polygonal lasso tool (this time you may want to be more careful than when doing the gradients). Save the selection as the beginning of a new saved set of selections, "Hatches".

    For a thorough tutorial on how to work with saved sets of selections (or "channels"), see Installment 2 of "Recolouring the Storch", and the following ones. It really is a most useful technique, as will be evident also from this exercise.

    When you have outlined all hatches, and added these selections one by one to your "Hatches" selection, load this saved set. Again, temporarily restore the opacity of the parts layer to 100 percent. In the "Gradients" layer, copy merged (incorporating all layers below), and paste. Simply call the new top layer "Hatches".


    Note that even if we bring down the opacity of this layer to 75 percent (the same as the parts layer), it is still too dark. This is because we have added this semi-transparent layer on top of the original. In order to retain the original parts layer intact (which should be a goal throughout), here's a neat trick:


    Load your saved selection of hatches again (now you're happy you went to the trouble of saving that selection, right?). Create a new layer immediately above the original parts layer and call it "White mask" or something like this. In that layer, fill the selection with white. Looks like above, if you temporarily shut down your "Hatches" layer.

    And if you turn it on again, it looks like this:


    Much better, isn't it? I've done one little further bit of alteration here, namely reduced the opacity of the hatches a bit further again, to just 65 percent. Thought they came out better that way, and it was so easy, now that we have them in a separate layer.

    But the main reason for going to all the trouble of separating them, of course was to be able to apply some 3D-effects to the hatches:


    For a thorough tutorial on how to achieve these 3D-effect, see Installment 3 of the Storch recolouring, and the following ones. From the screenshot above you can copy the values I inserted.

    Note that I arbitrarily assigned an "Up" bevel for the hatches. The bevel size is 4 px, and the light is set to come from 45 degrees front, and 45 degrees up. Adjust to your own liking for best subjective effect. But do keep in mind that you should try to imagine the part in its correct position - the eye is easy to fool with optical illusions!

    4. Amending the rivets

    To finish up, I went through the same rigmarole of saving a selection of all the rivets in the hatches. I outlined one rivet with the elliptical marquee tool (caps pressed to get a perfect circle), saved the first as the start of a "Rivets" selection, moved the selection, added to the saved selection, etc.

    For a thorough tutorial on rivets (and also a good recap of the general method of 3D effects), see Installment 6 of recolouring the Storch.

    Loading the saved "Rivets" selection, copying merged, pasting into a new "Rivets" layer, reducing opacity to 65 percent, and adding 3D-effects ("Down" direction and 2 px bevel size, same direction for light), produced the following:


    This is also what you should judge my efforts by so far. Opacity here has been reduced to 75 percent in the parts layer, and 65 percent in the rivets and hatches layers.

    Note that all options have been preserved. From here on in, you can experiment freely with different settings for opacity in the different layers, since they have been so carefully separated.

    These are the settings I have used for the entire kit (11 sheets of rearranged parts, since I - of course - ultimately intend to enlarge to 1/16).

    Final judgement, of course, has to be reserved until test printing. I haven't dared that yet. A consolation is, that if the test print turns out less than satisfactorily, I can just go back and adjust a few sliders in the documents for another try. We'll see.

  6. Gil

    Gil Active Member


    Just a quick note on using the magic wand, gradient, add noise, motion blur and blur. Downloaded the test figure and performed the image work on the same layer. Note that the rivets are smeared as a result of the quick and dirty selection process and no attempt at seam detail was tried. A cloud render or two was added to differentiate some of the panels. Also some were symmetrically selected on both sides and effects added to save some time. Not bad for a few minutes of first figuring out the strange Photoshop user interface and then happily ripping it out. I'm almost delirious it's so easy...,


  7. Ashrunner

    Ashrunner Member

    I can see now that this is going to be another of those "jaw dropping" threads which seem to constantly pop up on these forums.

    Between Leif's skills and Gil's "delirium," 8v) this should prove to be quite the thread.

    Looking forward to future installments.
  8. Leif Oh

    Leif Oh Member

    Gil, and everybody. Like Ash, I think the quote to remember here is "I'm almost delirious it is so easy".

    Your excellent result, Gil, also makes me empathize with all who still are wary about trying. I really need advice on how to use gaussian blur (or clouding, or other rendering effects - haven't gone near them so far), why and when, to what degree, and what a no-regrets approach would look like (i.e. always being able to revert to the original state, not spoiling what you've done so far).

    More, please, when you can.

  9. Gil

    Gil Active Member

    Leif, Ashrunner,

    It took a bit more time to get to the "no regrets" phase..., but persistence has paid off. It's still delirously easy, though a bit more involved..., the ability to "go back" is preserved allowing fore to aft editing to be accomplished. I'll set it down with a short Tut tomorrow. Below is a screen capture showing the results. Not all the outline strokes are edited correctly but that can easily be remedied now. The cloud render combined with gradient, gausian noise, motion blur and gaussian blur does do a nice trick. I must say I am very pleased with how things are turning out.

    Thanks again Leif for getting me pointed in the right direction on this project.


  10. Leif Oh

    Leif Oh Member

    Excellent - I see you are logged on again, Gil. Hope you got enough sleep in between! I just now noticed some extraordinary nice rivets, great improvement on the original!

  11. bholderman

    bholderman Member

    Has anyone ever tried trimming and sending aluminum foil through a printer?

  12. wunwinglow

    wunwinglow Active Member

    Yes. It doesn't work. It makes a mess! Gil has a magic mix which might work, although it might kill the metallic look. There is a range of products from which I have got but yet to try out, and there are a couple of producers who do metallic paper suitable for inkjet printers. Here in the UK I can get this from Letraset and Eurojet, the first has a nice flat aluminium finish, the Euro stuff is much shinier. I am sure there will be equivalent products in your area. The problem with these is of course there is no white, so you have to either paint on the inkaid white material and hope you can register the images, or print the markings on thin paper and stick them on like model kit decals. I think this could look really good if done carefully. The metallised paper will take a great image with outlines, shading, stains, panel lines and so on. Using browns and yellows, greys and blues, you can get some wonderful steel/titanium/bronze effects. But no white....... Nothing is ever simple, is it??!!

    Tim P
  13. bholderman

    bholderman Member


    I sort of figured. I assumed the ink prbably wouldn't fix, learning that from printing on the incorrect side of a photo paper once.

  14. dimas Karabas

    dimas Karabas Member

    Hi bholderman,

    If you do not have metallic paper the metallic look can be achieved by spray painting the paper with metallic auto paint. As featured in my production of La 11: page La 11.htm

    Ps. By the way, I did try to print on Metallic foil and my Epson printer printed very nicely with no mess. The only problem was the ink did not stay. I am sure you can use spray-paint to lock the ink. this is going to be my next experiment.
  15. Gil

    Gil Active Member

    As Yogi Berra said, "It's Deja Vu all over again"...,

    You can print on aluminum foil paper (the correct term) if it is coated with an inkjet receptor. The "magic formula" that Tim refers to is a mixture of PVA and Acrylic Gloss/Matte Medium with a drop of dish detergent and thinned with a little pure water. It preserves the "aluminum look" underneath well. The image below is an early printout of Nobi's Saab J-21 on aluminized paper. The several artifacts were solved by adjustments in the formulation. The surface requires a coating of acrylic matte spray to seal the surface after printing. The ink dries in several minutes coming out of the printer and is fairly durable.

    Spray painting paper with silver paint works but opens up a whole host of downstream problems with many still requiring a receptor coating...,

    I haven't yet attempted printing on aluminum tooling foil. There doesn't seem to be any reason why this won't work. Foggy thoughts of B-17G skins being pumped out of the printer still persist though...,

    Tim is right about what I call the "white decal problem"...,

    Back to using Photoshop for the "psuedo-aluminum skin look"...,


  16. Ashrunner

    Ashrunner Member

    Gil . . . when you finish your learning curve on the psuedo-aluminum skin look from Photoshop, please put it all together in one article for all to use. I am thinking of my "All Models of B-52s Fleet" I hope someday to do and most of the early birds had the aluminum skin which this information would be perfect for.

    I have been playing with Paint Shop Pro to get a similar look in the past, but haven't been able to come close what you are getting in Photoshop. Hopefully, this will help me with that quest.
  17. Boris

    Boris Member

    To Leif Oh

    Say , did you try to use the PEN tool instead of selection tools? The PEN gives you much more precise selecting and it has a lot more options for filling or stroking. For example you can set some work path on your model and then set the feather radius option let's say on 8-12 pixels and get perfect soft edges of camo borders without using gradient tool.
    More, for stroke option you can stroke your path with different tools such as paintbrush, dodge or burn tools wich can give you very interesting effects.
    I took a liberty to implify your ideas in my current repainting of Yak-9P and it looks very interesting.
  18. Leif Oh

    Leif Oh Member


    Thanks, great! I always knew there must be a better way. My problem is, you lost me already. Pen tool, yes. Haven't used that at all. What to do with it, I do not understand, unless walked through it. Which I can't very well expect.

    Same thing with Gil's expertise. Mention rendering effects, Gaussian blur, clouding - and I wouldn't know what to do with it, even if I now have found it in the menues. I have to be shown, hands on.

    That's why I write so asininely long tutorials. Must be a pain to read, but I just know I wouldn't know what to do with it if not illustrated with an example where it is put to use, how it is done, and why.

    Your work looks outstanding. I'm so glad that you found something of value and managed to put it to some good use. What, that you did not already know, did you find useful for your work?

  19. Boris

    Boris Member

    Hi Leif
    Actually , I used your ideas that you mentioned in your article about Storch to make three layers : one ,so called DOWN contanes all lines and panels that are ment to be as you call it recessed

    Second is the layer which contanes protruding lines and panels

    Now I do understand you when you say that you must be shown exactly what to do - I'm exactly the same.
    Here is some explanation about pen and path tools. Actually these tools are vector graphics based tools. The pen is capable of creating some compound curves using so called Bezier curve. It is a mathematical tool that says that every curved line can be created using two points and a tangent to a curve. Actually, after you get the idea how to work with pen it gets really comfortable.

    Now to get first point , left-click in needed place at the start of the curve.
    Then to create straight line , click on the finish point (if SHIFT is pressed than horisontal or vertical or 45 degrees line is created)

    That's it we created two points of our curve. Now we have to create a tangent. First we create a tangent point by left-clicking on created line

    then we drag the tangent point by pressing CTRL and left-clicking on the tangent point

    now, we got a curved line and now we will add additional tangent points to fit the path to the curve

    Now, we can continue creating straight lines to "close" the contour of a detail
    Right click and get a menu
    DELETE PATH - deletes created path itself
    MAKE SELECTION - transforms a path to selection
    FILL PATH - fills this path with color or pattern
    STROKE PATH - strokes this path with a choosen tool
    FREE TRANSFORM PATH- lets us to change the path, (shape, size, rotation etc)

    Two things are interesting for our need FILL PATH and STROKE PATH

    FILL PATH - after clicking this option you'll get this menu : (art10)
    If FEATHER RADIUS is set to 0 then the path will be filled exactly , setting this option to more than 0 makes the border of filling area fade around the path border , the larger the radius the smoother border.

    STROKE PATH - well, just check the drop-down list of tools (the tool "travels" on the middle of a path)

    Surely, the tool must be set beforehand

    Try to play with settings of pen to see what can be done
    To the right of pen tool there are vector based tools : rectangle, rounded rectangle, ellipse, poligon, line and custom shape. These are actually predefined shapes that were created using pen tool. Exact settings can be set on tool menu on the upper tool bar - just play with them a bit to see what is going on

    Hope this short article will help save time

    If something isn't clear, reply, and I'll try to explain
  20. Leif Oh

    Leif Oh Member

    Now, that's what I call an explanation and a tutorial. Thanks a million, Boris! Now I shall learn how to make a Bezier curve - always knew it was possible, never managed to learn how. With your help I will!

    (I'm on a Mac, so I'll use the opportunity to figure out the differences in keys in order to be able to communicate better in the future.)

    The operative word here, as I see it, is the option to transform the curve into a selection. Excellent! From there on in, I know how to proceed. Never saw that turn of events coming. Feels very liberating. This is a tip that surely will be of great practical importance for many (i.e. dunces like me; but then again, if we don't share these things, we'll remain dunces, won't we).

    I've seen the vector tools, like rectangles, etc., but always shunned them, since they added a layer (unnecessarily, I thought), and instead drew the figure by hand. Now I can start a complicated selection, e.g. by making a rectangle, then add extra points and modify the curve, then transform it into a selection and proceed like I used to. Excellent!

    I think the vector boys ought to be quite relieved to thear this. They can now work in an environment familiar to them for starters, then proceed into bitmap effects, like the ones we started out with in this thread.

    Many thanks again, I think this was a really important tip, and I truly valued it!


    PS. (edited in:) Success! I am no longer necessarily intimidated by vectors and Bezier curves! Great way of making selections:

    1. Choose pen tool, and path option.
    2. Click at the consecutive corners of the area you wish to select, plus again at the starting point to close the shape.
    3. Add extra anchor points for dragging by clicking in each curved section. Often one extra anchor point is enough.
    4. Adjust by pressing cmd/ctrl and drag the added anchor point(s). For this to work the shape you created needs to be active; be sure to have clicked in it!
    5. Right-click anywhere in the finished shape and choose "Transform into selection". Proceed from there on as with any selection.

    This is just to confirm that Boris' tutorial really works. I'm no longer quite the dunce I was just a little while ago. Thanks Boris!

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