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How do I resize and make line art smooth when blowing up line art in Photoshop?

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  • How do I resize and make line art smooth when blowing up line art in Photoshop?


    I am an fine artist and want to make large giclee-style canvas prints (e.g. 30in x 35in) of my art. The problem I have is, I draw the line art and ink it on an 8.5x11in piece of paper. When I scan it at 600 dpi on an HP scanner and then try to resize it to a very large to something that's big, like 30 inches by 35 inches, for example, the line art looks "grainy" and not smooth. I use "Perfect Resize 7 Professional" which has the fractal algorithm to blow up the line art, but lines still look grainy. The plugin was very expensive too, so I hoped it would solve my problem.

    So, how do I get the lines to look smooth at such a large size? Do I have to trace every hand drawn line over using the Photoshop paint tool? Is there any way I can smooth the lines out with a plugin of some sort?

    Please help me!

    Here are some things I tried:

    - Took the scanned TIFF image and imported it into Photoshop, used the "Perfect Resize 7 Professional" fractal plugin, but the lines look grainy.

    - Took the scanned TIFF and imported it into Illustrator. I converted the lines into vectors using Live Trace, hoping they would smooth out. Unfortunately they didn't.

    I don't get it, guys, how do you professionals make hand-drawn art printed on very large canvases, billboards and such to look smooth?

    I appreciate your advice and look forward to your help, I really need it


  • #2
    Hi arkitecht, welcome to GDF. I hope you'll find it useful and fun here.

    We ask all new members to read the threads posted HERE and HERE. They explain how the forum runs, the rules, frequently discussed topics and our inside jokes.

    PrintDriver is our grande format expert, and Bob has some great scanning ideas too. I'm sure they'll have advice for you. I'm sure they'll be along before too long.
    This post is brought to you by the letter E and the number 9. Those are the buttons I push to get a Twix out of the candy machine.
    "I put my heart and my soul into my work, and have lost my mind in the process."


    • #3
      You might try experimentation with Smart Objects, and vector shapes and masking. TutVid has various other tutorials that may help if the aforementioned don't.

      As for creating glicee prints, why are you inking them outside of Photoshop? Hold off on the color until you scan the line art into the computer, and create masks to help with the crisp lines. It will also make it easier to create line art in Illustrator and color accordingly. Coloring in Illustrator is a little more difficult than Photoshop, but you are working expressly in vector format (no resolution loss when reducing/expanding image). Additionally, if you color it digitally, you won't have any contrast problems, and create smoother gradients and sharper lines. It takes a little more practice to master than the traditional pen/brush/whatever medium on paper method, but allows you more flexibility (plus that handy-dandy "undo" feature).

      As for reducing the "grainy" feel of your line art, you can scan in your image, select the white space with your smart selection brush, lasso, and wand tools, then going to Select->Contract on your menu bar, and enter in a pixel value you feel is appropriate (dependant on the line thickness and resolution values), and hit the delete key. That should remove the "fuzziness" of the lines. You may have to go back in and repaint the finer lines, but that should remove the majority of the problem, especially if you pair it up with shapes and masks (these tools are your friends in more advanced projects).

      You can also use the pen and line tools in Photoshop, and said tools are associated with vector shapes and smart objects.

      Hope that helps you. Shoot me a pm if you need more insight.

      Last edited by palo1; 05-13-2012, 07:07 AM. Reason: incorrect terminology description. fliter->mask
      ~People like me are the reason people like you take medication~


      • #4
        Arkitecht, expanding on what Palo1 said, scanned images have fixed resolutions. When they're enlarged, they get blurry. Your 600-ppi scan, is just about as good as you're going to get. A scan at that resolution is going to pick up very fine detail in your line art, but still, the amount of that detail is limited, as is the sharpness of your lines and edges.

        As you enlarge the scan to bigger sizes that require interpolation to even higher resolution, the software has to invent data that isn't even there. It does this through a series of algorithms that make guesses as to what those new pixels should look like based upon the surrounding pixels. The plugin you have makes its guesses based upon fractal algorithms, which can deliver marginally better guesses than the simpler built-in algorithms of Photoshop. Still, it really isn't possible for any software to intelligently fill in the missing data needed for the higher resolutions.

        You're under the assumption that designers have some secret to enlarging these bitmapped scans, but your assumption is wrong — we don't.

        You're also under the assumption that large-format images on billboards and large banners and posters are sharp — they're not. Billboard photos, for example, have quite low resolutions, and are very fuzzy when seen up close. It's just that they're always seen from far away and might not appear to be any bigger than a piece of paper held at arms length. Your brain knows that the billboard is big, but in your actual field of vision, the billboard is not that big, so the resolution can be low, and the billboard will appear to be sharp until it's approached and viewed at a closer distance than normal.

        You didn't show us your line art, but assuming that it is truly line art — black and white with hard edges — there is actually a way to scale up the art with no decrease in resolution, but it involves a very different process from enlarging a scan. Instead, you need to create the art in a vector-based drawing program, like Adobe Illustrator.

        This would normally mean, drawing the line art on paper, as you've done, then scanning it in, as you've also done. The difference would be that you would import the scan into Illustrator, then redraw it (essentially trace it) with vector-based lines, shapes and fills. Vector art is resolution independent since it does not depend on pixels and depends, instead, on mathematical equations that remain constant regardless of the size. For example, a scanned images of the letter "A" when blown up to the size of a billboard will have very fuzzy and irregular edges. A vector-based letter "A" (nearly all digital typography is vector-based) will still be sharp.


        • #5
          There may be a way to do what you are trying to do—or at least coming close.
          I'm going to suggest combining a pre-computer method with a computer production method. Some of the other old wizards may have some additional thoughts—

          Without seeing your work, I'm having to assume a few things:
          I am assuming that you are producing fine-art quality line drawings that are solid black and white— and that you like the textures and the effects of conventional drawing tools, such as brush work and ink. I'm guessing that you are working 8.5 x 11 for convenience in scanning or maybe drawing.

          If this is the case—can you try working about 11 x 14 or a little larger? If so, enlarge the drawing to about two thirds of the eventual size with a PMT, to about the 18x 24 size range (or 16 x 20 range). A PMT is a photo mechanical transfer. That amounts to a good quality photostat. This PMT should be able to maintain the look of your art at a 150 % enlargement. So, at this stage you have your black and white art enlarged to interim size. This interim size could be scanned at a 600 dpi (to maintain clean edges) and printed as a giclee print at about the 20 x 30 to 30 x 38 size range you are looking for. Typically, a giclee 4 color print needs 200 dpi plus—preferably about 250 dpi.

          All you production experts around here will probably find a few holes in this but we did stuff similar to this before using computers. The reasoning for the interim size is to get a much larger, acceptable line drawing without dealing with pixels.

          And the trick is finding a place that can shoot a PMT. I'm sure some of us old guys know of a couple of possibilities.

          The sizes and percentages are all ballpark numbers.
          Last edited by sully1251; 05-13-2012, 12:35 PM.


          • #6
            Originally posted by sully1251 View Post
            I'm guessing that you are working 8.5 x 11 for convenience in scanning or maybe drawing.
            I'm also assuming that it is more necessity, as he probably doesn't have anything larger than a 8.5"x11" scanner.

            As <b> said, you can bring into Illustrator (which you mentioned that you have done) and still use Live Paint/Live Trace. As per the problem you mentioned about loss of quality of sharp lines as Illustrator tries to compensate for the natural ink bleed and the lossy (the naturally-occuring algorithms that try to fill in that missing data during the image capture once saves into a file format) by adding extra vector points.

            There are ways around this: I am assuming that, when you import the image to Illustrator, you are working on it after you resize it to larger than 8.5"x11"; Illustrator tries to create as simple paths as best a possible by using as much information it can get from the image--the more information in an image, the more complicated the paths, the more ragged the lines.

            As such, I would actually try reducing the dimensions of the image so you have less erroneous detail, as well as fine-tuning the amount of detail that is interpreted by the livetrace/paint presets. You will probably have to go in afterwards with the pen tool to refine the points and eliminate unnecessary points that are causing ragged lines, but once this is accomplished, you can enlarge or reduce the image without loss of quality (as the image will be vector).

            As for large canvases and billboards, what <b> said again: Large canvases such as the dimensions you are listing are usually around 300 dpi, but I've seen this number go higher (but rarely lower, and never below 200 dpi). 4'x6' typically have a resolution of 150-200 dpi, and billboard dpi can range anywhere from 12 to 600 dpi (depending on the size). A good rule of thumb is for every 1" to 1' conversion, the dpi usually remains constant. That being said, 1" at 300 dpi for traditional print is 1' at 300 dpi for a traditional billboard size (12'x24'), or 25 dpi (ballparking-- actual dpi varies with printers/optimal viewing range/size of billboard).

            That, or course, is assuming that you were working with raster images, rather than vector. I already made this point in my previous post.
            ~People like me are the reason people like you take medication~


            • #7
              Additionally, this ratio is not for every project.
              ~People like me are the reason people like you take medication~


              • #8
                Sully, I haven't heard mention of a PMT for at least 25 years. Does Kodak or Agfa even still make stat paper?

                I used to use the process you've described to make larger display-sized headlines from Letraset rub-down type. I'd rub down the largest size type I had, toss it in the stat camera, then blow it up to the size I needed. From there, I'd use a Rapidiograph pen and an X-Acto knife to clean up the edges and sharpen the corners. Sometimes I'd even make a PMT from the PMT for the finished mechanical, but geech, that was back before I even had whiskers, let alone grey hair.

                I don't know where you'd find a stat camera these days. Maybe one of the prepress or large format people here would know. I suppose it would be possible to do something similar with a larger-format xerographic copying machine and a harder-surface paper.


                • #9
                  I think I'd like to see a small sample of the line work in question. If it is JUST the linework and you want to blow it up roughly 400%, the best way is to scan it in greyscale first. THEN upsample that scan to 400%. Now stick a Threshold adjustment layer on top of that and find a good 'typical' detail area to view at 100% size. Okay? Now back to the scan layer, time to WHACK IT with Unsharp Masking, maybe a couple of hits. Keep an eye on the preview.

                  This is my standard way of handling fineline artwork like etchings, crosshatch work, etc. when going from a 300 ppi scan to say, 1200 dpi black and white (1 bit) line. It works better than the theory says it should. Go figure.

                  If you're going to Giclee, you probably want to stay in greyscale though -- I don't know if you're planning to layer this with a wash or colour layer. In any case, you probably don't want to flatten it down to a 1 -bit line image unless you're compositing in a layout app (like ID). In which case, maybe lose the Threshold layer and add a Curve adjustment for 'anti-aliased' looking edges. Tweak the curve to suit.


                  This works great for freehand type of lineart


                  • #10
                    Originally posted by <b> View Post
                    I don't know where you'd find a stat camera these days. Maybe one of the prepress or large format people here would know. I suppose it would be possible to do something similar with a larger-format xerographic copying machine and a harder-surface paper.
                    If they were going to go to this extent, wouldn't be better advised that they would take their work to a large-format scanning company that uses something like a Cruse scanner that has color balancing and shadow exclusion?

                    Just my opinion.
                    ~People like me are the reason people like you take medication~


                    • #11
                      There's another problem with line art you are all overlooking and that is the interaction of the ink with the paper. I enlarge old handrawn maps all the time. At some point, and it's not too large, you are going to see the unevenness of the line work, due to the tooth of the paper and the uneven pressure of the inking tool.

                      The ideal method is the old fashioned method of actually getting the work photographed to color transparency then scanning the transparency in a drum scanner at some obscenely high resolution, at least 2400ppi. This work flow is hard to find. I have one guy left in the Boston area that does it, and the photo shoot can get expensive so best to have a plan of attack and book a full or half day.

                      Most desktop scanners only scan to 300ppi and interpolate the rest. Even if it says 600, you need to determine if it is a true 600 (optical vs interpolated) and a scanner is only as good as the smaller number of the two given for it's optical resolution. If you are going to take these to the level of what is called true giclée (and that term means a lot of things these days, but more on that in a minute), you want to find a service bureau that can either flatbed scan these or cruze scan them. Though for something this small, the cost of a cruze scan is sorta...overkill. You use a cruze scanner for oversized stuff or for stuff that has a 3D texture to it such as a hand-brushed painting where the lights even out the high points...But anything for fine art eh?

                      Giclée. I can't tell you how much I hate that term. In the early 90s it was a glorified Iris print. Today, it's any of a number of glorified inkjet print processes, usually aqueous based. If you want them done right today, you have to look for a printer willing to run their machine on grass-grows-faster speed (at least 1200dpi) on archival paper or media with archival UV stable pigmented inks. You need to talk to them first to find out what their optimum resolution is for output. It might surprise you. It could be 200ppi or it could be 400ppi. Rarely 600ppi.

                      If I were a collector of line art, I'd prefer an etching or a high end litho over anything described as giclée, unless I knew who the printer was.


                      • #12
                        < b > On the PMT question: No, I haven't used a PMT since 1988 either but I know a couple of guys back in Ohio who are still able to pull one (or the equivalent) out of a hat when they have to for a friend of mine. As odd as my suggestion may have been—it would work.

                        Here are a few some random thoughts:
                        We really should be seeing a sample of the art. I was guessing that there may be textures in the line art (like a dry brush technique) that would be hard to duplicate in Illustrator. If the working size was a little larger than 8.5 x 11 (12 x 18 or 16 x 20 for example) you could probably get a good scan at the enlarged size. Some fine-art line drawings that are loose and with some brush texture are enhanced to a degree when enlarged—paper texture and all.

                        My watercolors are in the 17 x 28 size range—I have them scanned from the orininal art at actual size, using 300 dpi resolution, by a local digital graphics firm. Scans that size cost me about $50.00. The files wind up at about 135 Mb. I usually have to color correct them to some extent in Photoshop at full size.

                        PrintDriver: I respect your opinions— especially on production. You mentioned that if you were a collector of art you would prefer an etching or a high-end litho over a giclee. That's a reasonable opinion. However, there are good reasons for reproducing artwork as a giclee—assuming you are producing a true giclee. An Iris is not a giclee. I have most of my watercolors reproduced as giclees. The color from an Epson fine art printer is excellent and is as close to continuous tone as you can get. I can hardly tell some of the prints from the originals. The images are printed on watercolor paper and both the ink and the paper are achival. The ink used is reasonably UV stable. One of the best advantages for the artist is that you do not have to print a high quantity—as few as two or three at a time.
                        Last edited by sully1251; 05-13-2012, 09:34 PM.


                        • #13
                          Giclée started with Iris prints. There was a small window of time when Giclée was ONLY Iris prints.

                          And I would consider something called a Giclée to collect if I knew who printed it.
                          Considering over the years we've had far too many people on here printing their own stuff on a desktop epson and calling it a Giclée...not to mention professionally hearing of vendors who considered an HP5500 print as Giclée worthy...
                          I know a few photogs that do limited edition prints on the Epson you are talking about and they do them in house. Nice work. If I could afford them, I'd consider them.
                          Limited run is an advantage for the artist. Again as a collector, unless I knew the series was limited, no go.

                          As a side note, I once asked an Epson sales rep about their 200 year ink. He said, "...maybe it would last that long–in a box under your bed."

                          A that a stat camera? Not heard it called that, but I came into the game just as they were phasing out. Good luck on finding one of those. Most everyone I know has tossed their conventional camera equipment. Sad really. And for just the OP's reason. It is really difficult these days to find high quality large format stock imagery, or once found getting it scanned. I dread the day my one vendor tells me his drum scanner goes toes up. They don't plan on replacing it.
                          Last edited by PrintDriver; 05-14-2012, 05:57 AM.


                          • #14
                            Scan at the highest resolution possible. I wouldn't consider 600 ppi high enough resoultion for line art.

                            I'd be at a minimum of 1200 ppi just to get it to look as it does at normal size.

                            The best way to enlarge the size is at the scanning stage.

                            If you want to go from 8.5 inches to 30 inches

                            Then scan at 350% and I'd say AT LEAST 1200 ppi. But I'd go for 2400 ppi so I'd have more room to play.

                            If it's ok at that size - then you can start to bring down the resolution to get a smaller file size.

                            "May your hats fly as high as your dreams"Michael Scott


                            • #15
                              That should be 353% (rounded up)

                              "May your hats fly as high as your dreams"Michael Scott






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