Sunday, 21 November 2010

Sunday Surgery: (Not Quite) New Year's Resolution

A couple of days ago, Kyle Jones raised some excellent -- chiefly Manga Studio related -- questions that I thought were worth a Surgery session. I should stress that I don't use MS professionally (yet) but am more of an enthusiastic amateur. As such, I would unreservedly recommend Doug Hills' excellent book Manga Studio for Dummies as, effectively, the missing manual for this package.

Nonetheless, much of what Kyle is asking breaks down to a matter of resolution, about which I do know something.

Counter-intuitively, I'd like to deal with Kyle's last question first, since the answer informs much everything else.

"in Photoshop on my computer it was very difficult to digitally draw and ink anything much bigger than 300 dpi, but since Manga Studio handles larger dpi projects much better (and can easily handle 1200 dpi without slowing down), is there any point of overkill (or is bigger always better)? If one's computer can breeze through the 1200 dpi setting in Manga Studio, is there any reason to go less? (assuming it will ultimately be colored in Photoshop at a lower dpi)?"

This actually hits on something very important. There is an extraordinary amount of rubbish talked about resolution, and Kyle is exactly right when he refers to higher resolution as "overkill". As computers have become faster and hard drive space has become cheaper, there has been an automatic assumption that more is better. The last time I worked on pre-press, I was routinely being sent graphics files from agencies that were 3600dpi and higher.

This is crazy.

There's a very good reason why scanners offer very high resolution options: if you intend to scan an image and then digitally adjust it or scale it, then it makes sense to scan it at actual size but at high resolution, since making adjustments through the preview on a scanner's software interface is so imprecise as to be useless. Better to bring it into Photoshop at high resolution, adjust, scale, make other fine-tuned alterations and then reduce the dpi to the setting you need.

For this reason, comic line art is generally scanned at 600dpi and is (I suspect) the reason why 600dpi is the default resolution for Manga Studio layers.

But, as Kyle notes, the first thing most colourists will do is drop the resolution to 300dpi.

So… what is the ideal resolution for your documents? 

The answer is defined by the quality of the printed product. All printed material that has any kind of variation in colour or tone is made up of dots of ink on paper. The fineness of those dots in printing terms is defined by the screen frequency, which is measured in lines per inch or lpi.

There is a very complicated formula to enable conversion from dpi to lpi in order to work out optimum resolution, but I worked in newspaper and magazine production for ten years, and the rule of thumb which always worked in my experience is that, for an image that is 100% of printed size, optimum dpi = 2x printed lpi.

Old style B&W newsprint was anything from 45-75lpi

Most magazines are 100-120lpi

Really glossy brochures, art books and some high-end magazines might be as high as 150-175lpi.

I would be astonished if there is any comic on the market printing at higher than 150lpi on internal pages, and 175lpi on the front cover, so anything higher 350dpi (call it 400 if you think the artwork might be need to be scaled up at some point) at actual size is nothing more than a waste of hard drive space and CPU clock cycles. 

In almost all instances where the printed product will be colour or grayscale, 300dpi will be more than sufficient. If in serious doubt, find out what the lpi of the printed pages will be, but I'm prepared to bet cold, hard cash on the upper limit being 150lpi.

If you're creating aliased linework (with hard edges, of the kind that Manga Studio produces, for reasons explained in my previous post here) then you should do that at 600dpi -- if you were submitting traditional pen-and-ink work, that's what you'd be expected to scan it at, so it's as well to respect that as a convention. It's also important to note that the lpi to dpi conversion is only applicable to colour and grayscale documents. Absolute black and white is imaged in much more detail and 300dpi is insufficient in these circumstances.

(The two paragraphs above have been revised in line with some sage and timely advice from Mr Todd Klein, for whose input I am most grateful.) 

 "The brushes I had made in Photoshop were modeled after Freddie Williams' suggestions in his book "Digitally Drawing Comics". For instance, he suggested working in a 300 dpi project 11 x 17 inches and doing contour lines at 6 or 8 pixels as a starting point."

I will confess to being mystified as to why anyone would advise creating digital art from scratch on an oversized document -- the only difference it makes is to the Zoom percentages you have to use. In the layout, "pencilling" and "inking" stages, certainly in Manga Studio, I'd work at 600dpi and actual, printed size.

"What would be the millimeters of an 8 pixel or 3 pixel Photoshop brush in Manga Studio (if page size and resolution affects the brushes at all - which touches upon my next questions - then please assume the page size and dpi would be the same in both programs)?"

The resolution absolutely affects this. Pixels are the "d" (dots) in dpi, so the higher the dpi, the more tightly packed the dots and thus the smaller the pixels. Double the resolution and a brush measured in pixels shrinks to a quarter the size:

For reference, that 24px brush at 300dpi measures 2mm across, and 1mm across at 600dpi.

Manga Studio advises a very old-school way of determining "actual print size" on your monitor, which is to create a document and then adjust the zoom percentage on screen until the ruler at the top of the document matches an actual ruler that you hold against the screen. Once you've determined the zoom percentage that matches the real print dimensions, you can set this as the default value the application preferences and zoom to it with CMD-SHIFT-0 (zero):

Note that, dependent upon your own screen size and default resolution, the print size zoom percentage on your monitor is unlikely to be 16.4% -- you need to measure it yourself!

Manga Studio is much better at maintaining live updates of the same document in multiple windows than Photoshop, so it's worth creating two windows for your working document, one that you leave at Actual Print Size and the other that you do all the zooming in and out of, that way you can always quickly refer to how your linework will look on the finished page and ensure that your lines aren't becoming over-fiddly or insanely detailed. If you have a Cintiq or a dual monitor set up, you can keep the print size window for reference on the monitor that you don't use for the main drawing.

(This last hint shamelessly stolen wholesale from Mr Dave Gibbons' Manga Studio 'webinar' which you can see here, and which is well worth 90 minutes of your time.)

Because Manga Studio uses millimetres rather than pixels, MS brushes are the same size regardless of document resolution: 2mm is 2mm, resolution only changes how many pixels are squeezed into those 2mm.

I would genuinely advise trying to let go of the actual measurements of your pens and brushes, and simply worry about whether you're happy with the stroke weights they give at Actual Print Size.

Obviously, if you change the size of your document, then this will affect the size of your brushes and thus your strokes, which is why I recommend working at high resolution and actual size, rather than on an oversize document at lower resolution.

However, if you are determined to work on documents that are larger than printed size, the key thing to remember is that you are dealing with areas and not lengths. If you take a normal comic page and double the side lengths, you have increased the area by a factor of four.

Consequently, if you want to create a document that is twice the final, printed size of a comic page, you need to multiply the side lengths by the square root of two which, as near as makes no difference, is 1.4

Thus, if a comic page (including bleed) is 178mm x 269mm (sorry, US readers, the rest of the world is metric!) and you want to work on a page that is double that, you need to multiply each side by 1.4, to give 249mm x 377mm.

The same is true for brushes -- a 48px brush at actual size would need to be 48x1.4= 67px on a document scaled to two-up.

It's important to stress, though, that the whole point of artists working on oversize pages was originally to enable the artist to create finer strokes than they would be able to if they worked at actual size. The only reason for drawing at half or two up was so that the linework would appear finer when camera-ed down to actual size (and a certain amount of unevenness of line would also be eliminated). If you're going to scale up your brushes, you might as well not bother!

And that -- I think -- pretty much covers it. If any of this is unclear, or raises additional questions, then please use the Comments section to leave feedback and we'll come back to this in a future surgery session.




  1. Great post as always Jim, Please keep them coming!

  2. Wow, first of all Jim, thank you very much! I had to read this three or four times before I absorbed it all (and actually did some tests in Manga Studio & Photoshop for it to fully click, but when it did, I felt a great sensation that I was finally - and happily - really "getting" a lot of this technical theory so I’d be able to focus much more on creative - rather than on “am I doing this right?”). I've tried to find answers to these questions on the net previously (to no avail) - and mostly got “bigger is better” opinions which didn’t sound right to me. I think your post above should be required reading for all new aspiring comic artists!

    A few things I noticed when I was testing all this in Manga Studio that might be helpful to underline for people at a similar stage as I am ... Definitely measure your own screen's particular size. Mine for instance was 15.6% - close to Jim's, but certainly not the same. Also, when I tested that the default 15.6% was saved and would be there for other Manga Studio projects, I opened up a 1200 dpi project - whereas I had set the default Actual Page Size in a 600 dpi project. Sure enough, the 1200 dpi (when set at my new default) was double actual ruler size. That dovetails exactly with what Jim explains above concerning pixels and dpi. So if one is working on a project at a different dpi (than the one they set the Actual Page Size to), please remember to take out your ruler and re-measure.

    Also, the amazing tip to have two windows open at the same time (hats off to both Dave Gibbons and Jim on that one) - was a Holy Grail tip I was looking for without knowing I was looking for until it was shown to me (now I can happily forget about memorizing mm or pixel brush sizes and just go with what I like - looking at the Actual Page Size as reference). In case anyone doesn't know, to open two windows at once in Manga Studio, go to the top pull down menu ... Window -> New Window.

    I'd also feel remiss if I didn't stress that Freddie Williams' book has been a true inspiration to me - as well as offers lots of great advice (even if it does suggest working at 11 x 17 inches ... which I will respectively now choose to work at actual print size instead). Even though it was written with Photoshop in mind, a lot of the concepts (though not the precise steps) carry over to Manga Studio too.

    Lastly, a few quick follow up questions, Jim, whenever you get the chance ...

  3. ... Do you ink on a vector layer or a raster layer in Manga Studio. I realize you'd still have to use the bucket tool and some other things on a raster layer (even if inking with vector layers)? Do you do this (inking on vectors) in case you want to make characters or objects bigger as you adjust your drawings? Also, what would be the precise specs you'd recommend when building a standard US comic book page in Manga Studio (for Page Size, Finished Frame, Basic Frame and Bleed Width) as it seems different comic company's specs vary slightly, what would be a good generic template? And to address one last time why some people might recommend working at 11 x 17 inches, is it possible they might do so in order to have the option to print posters or larger installations of their comic art at some point - or keep open the door for perhaps future technologies where higher page size and/or dpi might be useful (and that would justify it)?

    Again Jim, thank you very much! I pulled an all-nighter working on my comic when I saw you responded to my questions. And was so psyched to find out the answers, put off sleep for a couple hours to absorb it all. As I think about comics all the time these days, I have more questions on different aspects of comic creation but will spare you them right now (sure you’re breathing a sigh of relief!) and save them for a later Surgery Post ... Thank you again, your site is awesome and the generosity with which you share both your time and insights makes me only want to “pay it forward” and help fellow aspiring comic artists too whenever and wherever I can!


    Kyle Jones

  4. Excellent and helpful as ever, Jim!

  5. I've always wondered about these things. The years spent in the pre-press departments of various titles really helps. Thank!-

  6. "Consequently, if you want to create a document that is twice the final, printed size of a comic page, you need to multiply the side lengths by the square root of two which, as near as makes no difference, is 1.4"

    For goodness sake, man- I'm a pencil monkey! My brain absolutely refuses, point blank, to make any kind of sense of such talk!


    Very interesting and informative, as usual. Thank you.

  7. Interesting stuff.

    I color in 600 dpi because it's so much nicer when you have very thing lines that tend to disappear with 300 dpi.
    And since photoshop doesn't have a "close small gaps" function on the paint bucket, it can get frustrating in 300dpi.
    But I had a question what the best way is to convert it to 300 once it's colored.
    When you do an image size, there is a choice between ways to scale it. The standard is bicubic, but this makes the black lines fuzzy. You can also choose for "nearest neighbor". And this keeps the lines very crisp. So I was wondering if this is better? I hope you can help me with this. There aren't many people out there who can give a straight answer about these things:)