Alpineandy said:
How do you get such neat cuts in plasticard, mine just seem to wander about.
I'm sure others have better answers but I find my cuts wander when I'm lazy and try and cut plastic rather than take my time and score it.
Use a decent steel rule, and a sharp blade. Make shallow light movements to score the top surface of the plastic then applying pressure from behind the cut snap the plastic along the score. You don't need to cut it all the way through. That takes longer and usually results in less than straight lines.
Windows are the same, score the 4 sides, usually a score only needs to be half the depth of the plastic.
Once the scoring is done, start at one corner and score to the centre, repeat for all 4 corners until the diagonal scores go all the way through creating a "diagonal cross" the 4 triangles formed can now be snapped out along the scored edges.
If anyone not use to using plasticard would be interested I could do some "how tos" with pictures, but I don't want to teach my grandma to suck eggs.