History of Scale Drawings - 1:18 (and 1:24) Series
As with the 1:36 series, the 1:18 series is based on a simple pixel-to-inch scale of 4 pixels per scale inch, or double the size of the 1:36 series. The scale when printed can therefore be obtained by dividing the print resolution (in PPI) by 4 - in other words, the scale is 1:(PPI/4). The 1:24 series was drawn at an intermediate size of 3 pixels per scale inch.
1:24 Series: An Evolutionary Step
The 1:24 drawings are no longer online, but they represented much of my drawing work in the middle of 2012. At the end of 2012, I replaced them with the 1:18 series.
The motivation for starting the 1:24 series in early 2012 was similar to that for starting the 1:36 series in 2008—namely, requests for higher-resolution drawings and reaching detail limitations in 1:36. Since the 1:36 series was already detailed and generally accurate, the 1:24 series represented an evolutionary step forward with finer details and corrections to the last dimensional discrepancies. The drawings were exactly 50% larger (3 pixels per scale inch) and were drawn in the same manner. For some parts in the 1:36 series that were already accurate, I simply enlarged and retraced them at higher resolution for the 1:24 series.
However, there were some additional steps and experiments along the way. I had tried several times in the past to create accurate vector drawings, and I tried again just prior to starting the 1:24 series. I made considerable progress on a vector image of an EMD GP40, more so than in any previous attempt at making vector drawings, eventually completing the front truck and basic cab outline of the locomotive. However, there was one major caveat: that very partial drawing required four days of work, which was painfully slow.
I then tried a GIF version of the same locomotive using my traditional drawing technique in MS Paint, but at the new scale of 3 pixels per inch—making the drawings similar in size to the 1:25 drawings of the Railroad Paintshop. I found I could complete the drawing about four times faster than the vector version, while achieving a comparable level of detail (albeit still pixelated). The 1:24 series therefore retained my traditional GIF drawing method while incorporating significantly finer detail than the 1:36 series.
Above: The first 1:24 drawing as it appeared following several minor revisions in the weeks following its initial completion. (Click the image for a full-size version.)
1:18 Series: Fine-tuned details
I worked with the 1:24 series for about nine months in 2012 and found it satisfying. However, the scale of 3 pixels per scale inch was awkward to use in a world of half- and quarter-inch dimensions, and I felt I could progress resolution one step further. As a result, over the course of three weeks in November 2012, I created 1:18 versions of all the 1:24 drawings I had done, using a new scale of 4 pixels per scale inch. To my knowledge, these drawings represent the largest raster-image train drawings on the Internet.
Above: To start the first 1:18 drawing, I took the first 1:24 GP40 and half traced/half redrew it at a larger scale. As a result, when reduced to the same size, it appears nearly identical to the 1:24 version. This drawing is currently listed in the main "Drawings" page and is representative of the current 1:18 series. By this point, four drawing scales (1:110, 1:55, 1:24 and 1:18) had made their debut with a generic B&O-style GP40.
Once again, I retained my traditional method of editing the drawings as GIF files in MS Paint. Since the 1:24 series was already very large, I discovered early on that I wasn't adding much additional detail—it was more a question of refining the lines. In fact, unlike the 1:36 and 1:24 series which were drawn mostly from scratch, the first drawings of the 1:18 series were made largely by tracing resized 1:24 drawings—hence the very short time delay for completing the initial batch. Also unlike the 1:36 and 1:24 series, the 1:18 series was designed to replace (rather than supplement) the previous scale. Since the 1:24 series was still in its infancy by the time I started the 1:18 series, I removed all the 1:24 drawings from the site and replaced them with 1:18 versions.
The higher resolution of the 1:18 series presents a few additional challenges. More so than in previous scales, I measure everything—which often results in a lot of time devoted to creating accurate renditions of relatively minor components. The drawings initially didn't fit vertically into my working screen resolution, which made scrolling and editing the labels more of a challenge - although with a monitor upgrade in 2015 (from 1440x900 to 1920x1200) that's no longer an issue. They also take up 4 times as much memory as the 1:36 series. However, those are minor compromises when the scale allows a level of detail that I could never achieve before.
Upon starting the first painted 1:18 drawing in late 2012, I made one minor (but significant) change to my painting methods in MS Paint—after I discovered the beauty of PNG images. Previously, I converted undecorated drawings from GIF to 24-bit Bitmap images for editing, and I only re-saved them as GIF files (custom palette) when they were completed. However, the size of the 1:18 drawings made them huge and laggy for editing as 24-bit Bitmaps, so I now convert the undecorated drawings first to 24-bit Bitmaps, then immediately to PNG files. When complete, I use another program (IrfanView) to compress the images, as MS Paint does not offer full PNG compression. The resulting PNG files maintain the full colour palette of Bitmaps yet take up less memory than GIF images.