Just for the sake of completeness, if you get a big chip in a guitar with a polyester finish you can fill it with nail varnish. If you want to make it less visible, take the guitar (or a piece that has chipped away) down to your local shop and find the best colour match. Carefully paint a couple of layers in the chip in the colour nail varnish, allowing plenty of time for it to fully dry between coats. Then switch to clear nail varnish to build of the finish, again making sure it has plenty of time to dry between applications. With a little patience you can make a very good repair that can be close to invisible.
And here's one I prepared earlier !
The two bottles are nail polish for my 15-year-old Squier Vista Series Musicmaster bass ;
Music is it's own reward .