How to scribe curved plastic surfaces?

[elysium64]

Hope you can help, i need to rescribe some Plastic doors on a smooth curved hard plastic surface...
What tools to use?
How to get a perfectly Straight line (can you buy steel flexible sticky tape??)
any advice greatly appreciatted.
Thanks

[Big Sexy]

Scribe as in cut or just looking to pencil out a pattern or something?  I think I've seen a flexible edge before for like drafting and stuff but I don't think it would work to cut with. 

[snitcythedog]

can you buy steel flexible sticky tape??

You can use a contour gauge to help you mark it with a pencil or scribe.

http://www.micromark.com/8-Inch-Plastic-Contour-Gauge-with-Interlocking-Ends,9578.html
Hope that helps.
Snitchy sends.

[OSHIROmodels]

Any piccys of what you are scribing? A picture is worth a thousand words etc 

cheers

James

[matakishi]

You can use label maker tape as a guide, you know, the plastic stuff that you punch letters into, Dymo.