I am new to using the thicker threads so I have been trying to deal with the thread exchange with samples and such.  I have bought some  from them but evidently not enough as he will not send me any more samples in an envelope, I guess it is not worth his time.  Bad business in my book, since I could do a great deal of business with him.   
I have since found another supplier and the guy is great to work with.  If you do not dealing with the thread exchange shoot me a PM and I will send you the other companies contact info. 
The Artisan.........