Photos by the author
So you haven't been able to find a paper model of your favorite airplane, or auto, or your own house? Why not design your own? If you have a drawing program on your home computer, its easy to get started. Aside from your research to find plans or measurements of your subject, and figuring the best way to translate the 3-dimensional form into two dimensions, one of your first decisions will be choosing the best computer program to draw your model.
One caveat before we begin: I must admit that I am not familiar with the particulars of each of the many choices of drawing programs out there, only the tools that I have used. There are numerous drawing software packages and many ways to create computer illustrations, but here I will describe just one way of drawing an illustration for a paper model. If you do not have access to one or two drawing programs mentioned below, you may still be able to use some of the techniques described.
For the general purposes of this article, we may divide most drawing programs into two types: raster or vector.
Raster vs. Vector Artwork
Raster-based paint programs such as Adobe Photoshop, Corel Painter, Paint Shop Pro, etc. create images made up of thousands of pixels in a grid. This is ideal for reproducing the subtle color shades of a photograph, but can be less than ideal for reproducing clean straight lines and legible written instructions for your model.
In order to produce clean, legible outlines for your model, set up the file at a high pixel resolution when you begin drawing. At least 300 dpi (dots per inch) is fine for a color illustration, but 1200 dpi is best for clean black & white outlines and text. What looks fine on the screen (72 dpi) when you are drawing your model may appear out-of-focus or jaggedy when printed out on a high-resolution printer (see fig. 1), resulting in a sloppy-looking paper model when it is completed.
The disadvantage of using a high resolution to set up your drawing is that the file size increases exponentially! A 8.5 x 11 image at 300 dpi will require 24MB of memory if it is not compressed when saved. If you are publishing your model on a CD this may not be a problem, but if you are posting it on the internet you'll have to be conscious of the file size using some form of image compression or file compression.
Using a raster paint program to create your illustration will allow you to paint in all the details and shades you desire onto the surfaces of your model, but it is often less helpful for drawing the basic shapes of the form when you are starting the model. If you discover after test building that the fit of the pieces would be improved by moving the fold lines a little to the left, it can be very difficult to select just the fold line in your illustration. And once you make a change to the shapes, there is usually no way to measure the pieces of your model to be sure that they will fit together precisely before printing to test it by hand.
One other drawback of a raster-based paper model is that it is limited in the size it may be printed. If you print a raster drawing at a larger scale, you will start to see the individual pixels. If someone chooses to print your model at a different scale, they may end up with a sloppy model, just as if you had created it at a low 72 dpi resolution. There is a limit to the amount you can enlarge raster artwork before it becomes an unrecognizable pixelly mess.
Vector-based drawing programs such as Adobe Illustrator, Corel Draw, Macromedia Freehand, etc. create images and shapes mathematically. The clean lines and edges will look clear when printed on any type of printer, and enlarged or reduced to any scale the viewer feels (see fig 2.).
Most vector drawing programs allow you to enter the exact length of your lines, squares and circles, making it easy to draw in the exact scale you want. You will be able to align the fold lines and pieces so they match precisely. If you know the dimensions of your subject, drawing the basic shape of the paper model will go quickly.
The main drawback to a vector-drawn model is that it is more difficult to paint the subtle shades and textures you may want to fill in the outlines of your design. Most vector drawing programs allow you to create gradient fills and freehand shapes, so if you are patient you will be able to draw in all the minute details you desire to make your model look lifelike or 3-dimensional. However, it is generally not as simple as using the paintbrush tool of a paint program to smudge in rusty shadows and sun-faded highlights on your model.
A second drawback of vector-based art is that there are no standards for sharing files in vector format. The artwork you create in Corel Draw will not be printable by anyone unless they own a copy of Corel Draw. While raster artwork can be saved in JPEG, GIF, or TIF formats which are readable by any paint program and any platform, there is no such standard for vector art.
Raster and Vector Forms Resolved
Fortunately, there are ways to make use of the advantages of both types of artwork if you want to make a sharp-looking model that is shaded and yet also crisp and sharp. Depending on your drawing software, this may take more or less extra work. Some drawing programs, such as Deneba Canvas, allow you to create artwork with both raster and vector elements together. Other programs, such as Adobe Illustrator and Adobe Photoshop, are integrated to allow swapping artwork back and forth with each other. You'll have to read your manual to find out exactly how your drawing and paint programs can work together. At the very least, if your vector drawing program allows you to place raster art, you will be able to create a hybrid illustration.
To get the best features of raster- and vector-based graphics in your paper model, first create the structure for the model in a vector drawing program. You can print this white outline and do several test builds to be sure the model works and fits correctly before adding any color or artwork.
Once you have the framework complete, place or import these outlines into your paint program. Depending on how your paint program works, you can place these outlines on a separate layer so that they are simply guidelines and do not become part of the artwork. Using the outline as a guide, create artwork to fill the particular shape of each piece with all the shading and details you desire.
Then, go back to your drawing program and place or import the raster artwork behind the vector framework, using the vector shapes to define the solid cut-out lines of your model, the fold lines, and any line you wish to print crisp and clear, such as step-by-step instructions or construction diagrams. Now you should have a composite artwork with the best of both forms of artwork. You'll be able to see all the fine detail and yet also keep the crisp clear outlines you started with.
Once you have completed your model, save it in its native file format to preserve the vector lines. In the next article, we will explore the different file formats you can use to share your paper model illustration with the rest of the world! (See attached file: VectorEnlarge.gif)(See attached file: RasterEnlarge.gif)
