How to Create a Flag Book Mockup in GIMP
I've been learning about flag books recently, since I'm going to be leading a session at HBAG about them in April. Since we're concentrating on using photographs in the flag book format, I thought it would be fun to have several different images available in the kits. That was all fine until I discovered how much time it takes to do a physical mockup.... I figured it should be pretty easy to do the mockup digitally, so I could get an idea about whether the image would be interesting or not when flagged.
I use GIMP, so these instructions are particular to that program. If anyone wants to adapt the instructions for some other program, be my guest. Just give me credit and a link if you use my images and text :-)
First Things First
I highly recommend the very thorough flag book article in the Fall 2005 issue of Bonefolder. Karen Hammer does a terrific job of explaining the structure, how to prepare and trim your printed pages, and assembly. Following her example, I'm creating a seven-page book.
This tutorial is just about creating a digital preview, in case you prefer to twiddle bits before cutting paper.
So Let's Start Mocking!
Open your image in GIMP and crop it to your liking. I think landscape ratios tend to work better than portrait ratios, but I don't think there is any technical reason to not use a portrait layout. I'm using a 1600 x 1200 pixel ratio.
Here's my original image:
I want each page to include a good amount of the image, and I want to end up using the whole width of the image. I need seven pages altogether, with each page including a subsequent section of the image.
I'm going to start with about 2/3 of the image on first page, and divide the remaining third amongst the rest of the pages. To do this, I'll add a grid to my image. Take the horizontal width of your image and divide it by 20, then set up a grid with this as the horizontal value and the full height of the image as the vertical value.
In GIMP, choose Image-->Configure Grid from the menu. Select a Line Style that isn't Crosshairs (I'm using Dashed in my example). Click the chain link under the Spacing values so that you can make a grid with different horizontal and vertical values. Enter the calculated width and height in pixels. Click OK.
If necessary, turn on Show Grid and Snap to Grid.
Each flag is going to be 14 divisions wide, and we'll travel across the image one division at a time, resulting in seven pages.
Now we need horizontal guidelines to set the height of the flags. I'm going to divide my picture into three sections, so I'll add two horizontal guides by dragging them down from the ruler. Place these wherever they seem to divide the picture nicely. Write down where the guidelines end up--you'll need to recreate them on another document later. The flags do not need to be all the same height--this is an artistic decision!
Now we need to create an empty document to drop our flags into. I'm going to make the folds of my spine equal to twice the horizontal increment of my image division (I'm going to call this "the creep"). So the width of my spine will be 32 x the creep (8 valleys in the accordion fold, with the side of each valley twice the creep). The flags will stick out on either side by 8 x the creep, so the total width is 48 x the creep, or 2.4 x the width of the original image.
My original image is 2592 pixels wide, so I'll create a blank document that is 6220 pixels wide and 1944 pixels high (same as the original).
Now we need to add a grid and guidelines to this document. The grid divisions will be twice as wide in the mockup document as they were on the original image. Either remember the width of those divisions and multiply by two, or take the width of the new document and divide by 24. Set the grid on this document the same way you did on the original image.
We also need to duplicate the horizontal guidelines onto the mockup document. If you don't remember exactly where you placed them, just grab one and move it around a little bit. The exact location of your cursor will show in the bottom left corner of the image window; the vertical value is the second one. Drop it where you want it to be, and remember this value. Create a guide in the same place on the other document.
Now it's time to make some flags!
Select your original image and choose the rectangular selection tool (R on the keyboard). Make sure the options are Replace Current Selection, no Feathering, and Free Select.
Select the left-most 14 sections from the top guide up to the top of the image. This will be the first top-section flag. (Make sure Snap to Guides and Snap to Grid are both turned on.)
Now copy this flag to a new layer on the mockup document.
- Ctrl-C on the original document (copy to the clipboard)
- Ctrl-V on the mockup document (paste from clipboard)
- Choose Layers-->New Layer from the menu (create a new layer based on the selection)
Switch to the Move tool (M on keyboard) and drag this flag to the upper left corner. Rename the layer "t1" (double-click on the layer name in the Layers dialog to edit the name).
Now we just need to create, copy and position six more top-section flags.
Switch back to the original image. Put your cursor inside the selection and press and hold the Alt key. This will let you move the selection (as opposed to moving the piece of the image that is in the selection). Drag the selection one division to the right.
Repeat the copy/paste steps above to add this flag to a new layer on the mockup document. Position the left edge of this flag two divisions from the left edge of the first flag. Name this layer "t2".
Do this five more times (scoot the selection on the original image, copy to new layer on mockup, position on the mockup) to create seven top-section flags.
Now do the same procedure for the bottom section. Again, start from the left of the original image and on the mockup. Name these sections b1 - b7.
The middle section will go the other direction, so this time, start from the right of the original image and the right of the mockup.
Place all the middle-section flags on the mockup, and you'll have an idea of what this image will look like assembled as a flag book! (Hide the guides and grid for a cleaner visual.)
So now we've seen what the image will look like if you start with the top flag section flopping to the left. If you don't like the way this looks, you can switch the direction; have the top and bottom sections flop right and the middle section flop left.
To do this, you'll need to do two things for each section.
- Switch the order of the layers
- Move the layers to the opposite edge of the mockup document
When we created the original mockup, we created layer t1 before layer t2. This means layer t2 is "on top of" layer t1. Layer t2 partially obscures layer t2. If we're going to flop the top section in the opposite direction, we need later t2 to be on top of layer t1.
Here is the same image, flopped the other way. Note that the right-most middle flag is on top, and the left-most top and bottom flags are on top.
Okay, great! Now how do I make it real?
Whether you're going to assemble your flag book "flop left" or "flop right," the flags themselves are exactly the same. It's all in how you put it together. So basically, just scale your mockup to the print size that you want, and then copy the flags at that size into a print layout document. Print that document, cut out your flags, and away you go :-)
If you've used the same proportions as I have (20 small divisions on the original and 24 twice-as-wide divisions on the mockup) then the ratios are as follows:
- Width of the fully-extended flag book = 24 large divisions
- Width of spine = 16 large divisions
- Width of flag = 7 large divisions
So you can decide your print size based on any of those. Let's say you want the spine to be 8 inches wide. Then the fully extended book will be 12 inches wide (8 in x 1.5) and each flag will be 3.5 inches wide (8 in x .4375).
Using the Scale Image dialog (Image-->Scale Image from the menu) I'll set my image to a total width of 12 inches at 300 dpi.
Now I can create a new 8.5 x 11 document, also at 300 dpi, and copy the individual flags into it to create a print page (or however many you need to fit all your flags).
Note: Make sure to observe the grain direction of your paper. Karen Hammer's article in the Bonefolder suggests aligning the length of the flags with the grain of the paper.