The answer to the question?
It depends upon which ester of TT your using as the solute. Why because as more TT is added to the oil a precipitate occurs especially when the solution is cooled.
But as a general rule the lower molecular weight esters, acetate and propionate are relatively insoluble and not much more than 100mg/ml will dissolve before precipitation occurs.
The larger esters, cypionate, enanthate, and decnonate are much more soluble and dilutions of 250/300/400 mg/ml are usually
achievable before precip occurs.
One can improve the solubility characteristics of the TT-ester chosen by either using an oil with a higher LD/50, safflower oil is one example.
However it's obviously quite expensive to use "in volume", so many UGL opt for more Benzyl Alcohol, which is a frequent cause of PIP in T-p or T-a, but BA is cheap.
Moral of the story, labs that sell AAS with PIP are cheap asses, and are best avoided IMO.
Regs
Jim