An experiment with full panel decals as an alternative to traditional lining methods.
The idea for this experimental blog came after a second attempt at lining the Beattie Well Tank.
I've often heard it said that lining rolling stock takes practice, practice practice, but I didn't want to spend the rest of my life re-spraying and lining a Beattie Well Tank, I'd sooner spend that time building, building, building, also the Beattie Well Tank required bespoke graphics that would be impossible for me to achieve with a ruling pen or brush. Commercial screen printed / tampo printed decals have been around for a very long time and in my mind provide an acceptable alternative for the likes of me that lacks the skill of the pen, but that wouldn't overcome the issue of bespoke graphics. A short while ago, attempts to produce decals with an ink jet printer with replacement cartridges gave unacceptable results and the cost of original cartridges was enough to put a stop to investigating further. Recently, I made a purchase on the bay for a second hand HP laser jet Pro 300 colour printer with non original toners, which will be used to produce decals in this experimental blog for a variety of models, first of which will be the Beattie Well Tank.
It is intended to produce the artworks for the decals in the same resolution as the printer, the printer is 600 dots per inch ( DPI ), so initial artworks will be 600 pixels per inch, if in practice, this resolution is to low, then the resolution will be doubled to 1200 pixels per inch. It is hoped that doubling the size of the artwork can be avoided, because scaling algorithms can produce unwanted dithering effects, for instance a line that is 3 pixels in width does not divide by two, so pixel colours are substituted to give the impression of correct width. Using Adobe Photoshop, presuming that 600 pixels per inch is fine for the artwork masters, with an image loaded, select 'image' > 'image size' to open the dialog, deselect 'Resample Image' flag and set the 'Resolution' to 600 pixels / inch, the image will now print to the correct scale, another tool used when creating rads and curves was the pen along with one of its associates, 'Add Anchor Point'.
Two types of decal papers for use with a laser printer were purchased, one of these was clear water slide ( transparent ) and the other was white backed water slide. Both types of paper have a white backing sheet so at a glance, they look identical. The reason for the white backed decal paper is that most printers do not print white, if the colour white is required in your decal design, then white backed decal paper would be required unless you paint certain areas of your model white. It became apparent during the initial decal printouts that by selecting different print paper types in the printer options dialog box, it was possible to alter the amount of heat used to fuse the toner to the print media, if not enough heat is applied, then the toner has less adhesion, two much heat and discolouration of the toner is visible. 'Colour Laser Transparency' paper type option was selected for the clear decal paper which turned the black borders of the decal a dark brown, adhesion was very good, while 'envelope' paper type option was selected for the white decal paper and although the colours were very good, adhesion was poor and toner could easily be removed with a finger nail. After a little trial and error, acceptable adhesion and colours were obtained with 'Opaque Film' paper type, the full settings were, Paper Size > Envelope No 10, Paper Type > Opaque Film, Orientation > Landscape and under the colour tab : Colours Themes > PhotoS.
Some Weeks Later : With the Beattie and Coffee Pot complete as regards to this experiment, an idea of lining the printed decals sprung to mind, using the existing artwork as a test, thin yellow lines were drawn in Humbrol Gloss 7 using a ruling pen over the artwork printed on clear decal paper. This worked out better than expected, being able to draw lines on a flat surface with the aid of a rule helped a lot, corners were cleaned up with a small brush dampened with white spirit, the paint took to the printed surface very well and did not smudge or damage the underlying artwork, with this method, multiple copies of the panels could be included in the artwork, in case of mistakes. Another option that might be worth considering is to spray the decal paper in the required livery and then laser print panel guide lines / borders for cutting and lining, this is an idea that I may try in the near future. Next in line came an incomplete scratchbuilt Manning Wardle 0:6:0 loco which needed a few minor modeling details adding before it could become the next victim for these trials. A decision was taken to be a little more adventurous with the artwork and add quite a few full panel decals for the boiler, sandbox's, tool box, bunker sides and back, cab sides and saddle tank. As before, artwork was first printed out on plane paper, the decals cutout and checked against the model before printing the actual decals on white backed decal paper. One problem that became evident when fitting the decals was that if a decal was cut slightly oversize, it would not sit tight in the corners, so checking the actual decal with the model prior to fitting is also important.
A simple test was done using a scratchbuilt sign board from a previous layout of Wool Station, the sign board was first sprayed in white primer followed by a coat of Revell 56 matt blue. The camera was set for internal lighting and the resulting photograph was imported into adobe photoshop were the medium tones of the image were sampled with the eyedropper tool. A second colour sample was obtained by searching google for Revell 56 matt blue and the third sample was a colour used on the Charles Rhodes horse drawn cabs, which when making comparisons between the printed decal and the newly printed sign board, looked pretty close. The three sign board artworks were added to the Charles Rhodes cab artwork and labeled 'EYEDROPPER', 'REVELL SAMPLE' and 'LOOKS CLOSE'.
Although the results obtained were satisfactory, there are a few points worth mentioning, the printer used in this experiment had a 600 dpi resolution and pixelation was slightly noticeable to the naked eye and very apparent with a magnifying glass, there's no doubt that the latest printers with typical resolutions of 1200 dpi would make pixelation less obvious, for me, the second downside was the lack of strength or vividness to the colours. That aside, I will continue to experiment along these lines and blog anything that might be of interest.