Scribing a perfect line? arggh

Having a little trouble with this... was fabricating this custom rear panel, and accidentally got a little putty in the trunk panel line... no big deal,though maybe I should've dug it out as soon as I realised it was there, while the putty was still tacky... anyway, so it tried, and I tried re-scribing it with both a hobby knife and a dental pic... while it's hard to see in the pic below, the driver side looks fine, and then on the passenger side the scribe is somewhat wider and, to the far right, I messed up and it went a little squiggly. Obviously I could fill the whole thing in with putty and start over, but how do you scribed perfectly straight lines? I really can't see myself trying to balance a ruler along the trunklid of the car as it's in my hand :grinno: ... any other ideas?

EDIT: oops, here's the pic :grinno:

http://www.efnetcars.com/album/temp/ajl.jpg

I have never tried this myself (cos I've never rescribed a line:) ) but I read it somewhere and it stayed in my mind as a good idea.
The author used Dymo labeling tape as a scribing guide (the stuff that you "punch" white letters into with the machine to make labels) like this
http://catalogue.rbs.org.au/catalog/catalog/1547.jpg
He said that it doesn't stick too hard to the model (check that though) and that it has a good stiffness and height to put the blade up against as you scribe down.
HTH but I think test first :)

For panel lines you need to have something like this.
http://www.scaleracecars.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=srcscriber&Category_Code=srcpe1&Store_Code=S
and the most important thing is that you don't push, you will need to pass through the panel line more then 20 times to get shalow grove and for the deep ones a lot more. If you push blade will stuck in plastic and line will become iregular. As Stevenski said tape can come handy if there is no line at all to start with, but also be very very gentle with first few passes, just scratch the plastic and again and again untill you feel it goes easily through the line. Modeling knife is not good for this because it doesn't push plastic out of the panel line.

Thanks guys I'll give that a try!

Definitely go for the Dymo tape. It's pretty tacky, but so far it's never pulled up any paint on me. Doesn't need to be stuck down for very long.

One thing though... if you're going to fill in your mistakes, I suggest an epoxy putty like Milliput, or else CA glue. If you use CA, then make sure you use accellerator and sand it down right-away (within minutes). If you don't, the CA will dry rock hard and be very difficult to sand (you'll likely damage the surrounding plastic more than the CA filler...). My experience with normal putty filler has not been good. Doesn't take scribing very well, and usually ends up looking worse than when I started.


Murray

i put a straight pin, in a pin vise and use that, works great!

The window trim door lines and rear cowl were all scribed with a Scale Race Cars scriber. These are only 6 thousands thick and because they actually have a cutting edge on them they remove a small depth with each pass. Needles tend to remove some then the groove gets wider and just pushes the plastic or in this case resin. With a cut this thin you can get nice looking lines with depth but you do not have to darken the lines later.
http://www.scaleracecars.com/forums/attachment.php?attachmentid=2902
http://www.scaleracecars.com/forums/attachment.php?attachmentid=2902