Tuesday 13 November 2012
Black line scans
Results of scanning below. These were initially 1200dpi but are now only 150dpi just for emailing and posting here.
Scanning
Having inked in the comic book pages on the bristol board the next stage was to scan them.
1. Scanning at 1200dpi as Black and White worked. That gives a bitmap image, which means the image is just one level of colour, which is pure black on white. Since this is the lowest level of colour information you can be greedy and scan at a very high resolution and still have a small file size. My scanner has a maximum of 1200dpi but 2400 would not be uncommon for black line illustrations. The pixels on a bitmap image will always be stepped (jagged) since there are no intermediate greys to smooth out the curved lines (called anti-aliasing). This makes it very important to scan at the highest possible resolution so the pixel steps are so small they do not appear jagged.
The blue construction lines disappeared since the scanner in the above mode will deem them to be too light to be black and so will treat them as white.
2. Scanning in greyscale didn't work. In this mode the scanner treats the image as a range of greys. The black ink line will be black but the blue pencil will be light grey. Trying to then use Levels and Contrast in Photoshop to get rid of these light grey lines whilst retaining the black is not so straightforward. It can be done, but the final lines left behind were no better than the top method, and may have started to break up a bit with application of high contrast.
Scanning in Greyscale at 1200dpi gives a much bigger file size (more levels of shades in the file), so takes ages. Scan at a lower res, say 600dpi works, but then the lines loose in sharpness what they might gain with the 'antialiasing' smoothing.
3. Scanning in colour works. Quite interesting. With this number of colour levels 1200dpi is out of the question, but 600dpi was manageable. With the colour file in Photoshop you will have real black line and blue pencil lines. So all you have to do is to eliminate the blue. For some odd reason in RGB the blue channel didn't seem to represent the blue! Convert to CMYK mode in Photoshop solved this.
(Note in Photoshop there are 'channels' for each primary colour which mix to make the full spectrum of colours. They are Cyan, Magenta, Yellow and Black)
Now the light blue pencils I use are in fact Cyan (light blue) and so all appear only in the Cyan channel. Brilliant, just delete all of this channel and the pencils are gone leaving just the black.
Well actually not quite. Maybe it just my basic desktop scanner, but the black ink line doesn't appear only in the Black channel, they also appear in the Cyan. So once the pencil lines had been removed by lightening up or deleting the Cyan channel then the black line became lighter, ie grey. The final image contrast now had to be to get the lines back to black. I thought affected the line quality and certainly wasn't any better than the above two methods. Shame, I think better scanners would separate the black and blue better since I believe this is the normal method used by artists.
So I used method one at 1200dpi. Then for colouring up I made a duplicate changed the mode to greyscale and reduced the file to 300dpi. This way I get the advantage of pin sharp 1200dpi initial scan, and then by converting to greyscale I have the benefit of antialiasing when the image scales down.
It has to be scaled down in order to have a manageable file size for colour, and my Mac couldn't cope with 600dpi and lots of layers.
Next the file is changed into CMYK mode, ready for colouring in Photoshop.
1. Scanning at 1200dpi as Black and White worked. That gives a bitmap image, which means the image is just one level of colour, which is pure black on white. Since this is the lowest level of colour information you can be greedy and scan at a very high resolution and still have a small file size. My scanner has a maximum of 1200dpi but 2400 would not be uncommon for black line illustrations. The pixels on a bitmap image will always be stepped (jagged) since there are no intermediate greys to smooth out the curved lines (called anti-aliasing). This makes it very important to scan at the highest possible resolution so the pixel steps are so small they do not appear jagged.
The blue construction lines disappeared since the scanner in the above mode will deem them to be too light to be black and so will treat them as white.
2. Scanning in greyscale didn't work. In this mode the scanner treats the image as a range of greys. The black ink line will be black but the blue pencil will be light grey. Trying to then use Levels and Contrast in Photoshop to get rid of these light grey lines whilst retaining the black is not so straightforward. It can be done, but the final lines left behind were no better than the top method, and may have started to break up a bit with application of high contrast.
Scanning in Greyscale at 1200dpi gives a much bigger file size (more levels of shades in the file), so takes ages. Scan at a lower res, say 600dpi works, but then the lines loose in sharpness what they might gain with the 'antialiasing' smoothing.
3. Scanning in colour works. Quite interesting. With this number of colour levels 1200dpi is out of the question, but 600dpi was manageable. With the colour file in Photoshop you will have real black line and blue pencil lines. So all you have to do is to eliminate the blue. For some odd reason in RGB the blue channel didn't seem to represent the blue! Convert to CMYK mode in Photoshop solved this.
(Note in Photoshop there are 'channels' for each primary colour which mix to make the full spectrum of colours. They are Cyan, Magenta, Yellow and Black)
Now the light blue pencils I use are in fact Cyan (light blue) and so all appear only in the Cyan channel. Brilliant, just delete all of this channel and the pencils are gone leaving just the black.
Well actually not quite. Maybe it just my basic desktop scanner, but the black ink line doesn't appear only in the Black channel, they also appear in the Cyan. So once the pencil lines had been removed by lightening up or deleting the Cyan channel then the black line became lighter, ie grey. The final image contrast now had to be to get the lines back to black. I thought affected the line quality and certainly wasn't any better than the above two methods. Shame, I think better scanners would separate the black and blue better since I believe this is the normal method used by artists.
So I used method one at 1200dpi. Then for colouring up I made a duplicate changed the mode to greyscale and reduced the file to 300dpi. This way I get the advantage of pin sharp 1200dpi initial scan, and then by converting to greyscale I have the benefit of antialiasing when the image scales down.
It has to be scaled down in order to have a manageable file size for colour, and my Mac couldn't cope with 600dpi and lots of layers.
Next the file is changed into CMYK mode, ready for colouring in Photoshop.
Sunday 4 November 2012
Comic Book Course
Just finished the last of six evening classes in Comic Book Drawing, at CityLit – London. Really useful course which really made me think, and a very good tutor in Matt Boyce. Drawing from imagination is quite a challenge, especially if you need to do figure work without reference. But somehow not having to dig around for ref photos (or worse, becoming a slave to Google searches) was liberating. We (the class) for our main project had to produce a four page comic book story to a standard US size, which is a lot more work than it sounds!
Although I've recently tried techniques such as inking with a fountain pen, using pencil on drafting film, or deleting the line work leaving just a fill, I ended up sticking to the traditional approved method! It sort of goes like this:–
1. Draw out the entire page of the book on a single sheet of A3 Bristol board within a 10 x 15 inch perimeter using a light blue pencil.
2. Ink over the pencil with indian ink using instrument of choice.
3. Scan greyscale or line art, and place image into final page layout at 60% of size (6 x 9 inch). The light blue pencil should not come out on the scan, leaving just pure black lineart.
It's a big advantage to plan everything on the page, rather than making separate illustrations and putting them together in a page layout software like InDesign. Not only is it quicker but you get an immediate feel for balance and composition on the page. The challenge is drawing straight onto the final illustration surface with confidence, it's not easy to relax into.
Pleased to say that the 1068A Gillot dip pen nib worked a treat with ordinary indian ink (see previous post 'Ink'). Also used a Gillot 303 for finer lines. I even found a use for my fountain pen loaded with Pelican Fount India ink, just to do the freehand rules around the story panels. So despite my doubts the ink didn't dry in the pen (needed some coaxing into life) and is black enough.
The story is a bit contrived, sort of mystery/action, but it starts with a drawing of a real disused hotel on the South Wales coastline, near to where I grew up. I took some digi photos of the blue pencil under drawing, in colour so the blue shows. Even so the lines don't show very well but the results are below. They are now inked in, so tomorrow I'll be doing the hires scans. I've not put the text in yet, I think I'll cheat and use a font and drop it in later.
Although I've recently tried techniques such as inking with a fountain pen, using pencil on drafting film, or deleting the line work leaving just a fill, I ended up sticking to the traditional approved method! It sort of goes like this:–
1. Draw out the entire page of the book on a single sheet of A3 Bristol board within a 10 x 15 inch perimeter using a light blue pencil.
2. Ink over the pencil with indian ink using instrument of choice.
3. Scan greyscale or line art, and place image into final page layout at 60% of size (6 x 9 inch). The light blue pencil should not come out on the scan, leaving just pure black lineart.
It's a big advantage to plan everything on the page, rather than making separate illustrations and putting them together in a page layout software like InDesign. Not only is it quicker but you get an immediate feel for balance and composition on the page. The challenge is drawing straight onto the final illustration surface with confidence, it's not easy to relax into.
Pleased to say that the 1068A Gillot dip pen nib worked a treat with ordinary indian ink (see previous post 'Ink'). Also used a Gillot 303 for finer lines. I even found a use for my fountain pen loaded with Pelican Fount India ink, just to do the freehand rules around the story panels. So despite my doubts the ink didn't dry in the pen (needed some coaxing into life) and is black enough.
The story is a bit contrived, sort of mystery/action, but it starts with a drawing of a real disused hotel on the South Wales coastline, near to where I grew up. I took some digi photos of the blue pencil under drawing, in colour so the blue shows. Even so the lines don't show very well but the results are below. They are now inked in, so tomorrow I'll be doing the hires scans. I've not put the text in yet, I think I'll cheat and use a font and drop it in later.
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