Thanks Hanaldo and Scott, I will improve the application of the reinforcement and look at a pigment filler. (the parts are non structural so I'm not too worried about stress cracks)

Black magic was probably used which is a black resin filler. Iirc its called 3m 212 or 210 resin. 

They possibly used a tinted polish like Turtle Wax Colour Magic or Pai Crystal Easy Gloss. These can help to disguise voids quite well. 

 It has taken a while!!  So after extending the mould edges and using fusionfix I have been able to get pretty reasonable results. But I am having the age old problem of slight voids, where the reinforcement is not flush to the surface. Perhaps with some practice this will lessen.

Thank you for the replies, it all makes sense. I am adding an extra flange to the mould though, as the was only a couple of centimeters space between the part and the edge and it made it really awkward to get the stack of reinforcement in position. Once I have made the part I will let you know.

yes, less is more when it comes to spray adhesive.

if used in good amount, which mean as less as possible, and not spraying on the mouldside you shouldn't have problems

Matthieu Libeert
Founder MAT2 Composites X Sports
website: www.mat2composites.com

You should have enough flange on there, just trim your materials after you get it fixed into the mold.  Using tape and a thin coat of spray adhesive will work great.

Thanks Matthieu, I think to do that I will need to make the flanges bigger on the mould and give it a go with the infusion as I am not set up for prepreg (which probably would be the best idea).