As Laurie asked, here are the results of my experiments. I have put them as a tutorial at:
http://www.scale-models.co.uk/threads/using-inkjet-printable-decal-sheet.27277/
Test decals (both plain coloured and my bur walnut) were successful. They shrank down closely on to a piece of Slater's plasticard embossed with bricks (showing the indentations which are like panel lines), and stuck firmly even when I tried to scrape them off with a fingernail. So far so good (as the suicide said as he passed the 20th floor).
However, the attempt to apply a single sheet of decal to my 1/16 Rolls Royce dashboard (see photo below, before decaling) was a complete failure. It failed completely to shrink back. This is not surprising due to the many lumps and bumps on it which prevented the decal from making sufficient contact with the plastic. It just draped itself loosely.
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So, what to do? Detail in the instrument panel at this large scale is important but I am trying not to be too obsessive! I could try several ways:
1. Sand away all surface detail, add the decal in one piece for surfaces A and B together (I have tested that and it shrinks back OK), and another piece for surface C cut to a curve and taking it accurately up to the edge of the decaling on part B.
Then glue on the detail. The glove box on the left could be a piece of pre-decaled poly card just thick enough to show proud, with its knob glued on and painted black (or aluminium to simulate chrome). The ovally-shaped surround to the instrument panel could be made from some black painted 22 gauge copper wire that I have—just the right size, and it holds a bend without springing back although it kinks easily. The other lumps and bumps could be made (but not in such detail) from tiny pieces of pre-painted polycard or wire glued on.
2. Scratch build the whole thing from polycard. One item with parts A and B glued together, and another item for C. Apply the decal to the first item, then to the second, then glue them together. Then add the surface detail as above. This might be safer, being non-destructive.
Any thoughts?
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