Homebrew PCBs

Hi all,

I have a question about TT.
The today's board i had to transfer twice, and even the second time was 
not perfect.
The toner did not stick in places, and was very brittle. it came off in 
hard "plates".

I had this effect a week ago with the last pcb too, but only very light.
this week the first transfer was not useable at all.


I have not changed anything and several boards worked very well before.

WHY? HELP?

I do not want to be placed back to the starting line again, it worked so 
well already.


I did the cleaning as always, very fine sanding paper and then degreasing 
with solvent.


Any ideas welcome. If it does stay that bad i have to go back to 
experimenting again.
(changing one variable at the time and checking)

I would like to avoid this, if i can pinpoint the source of the problem in 
another way.

I did not change the toner, or the paper, or anything. the toner is so 
brittle
if you correct spots with a ohp pen it scratches off the adjacent toner.

With my previous boards the toner appeared more like plastic, flexible.

Thanks for any hint..

ST