Black/Dark Colors not Printing Correctly on Mugs

[TaylordPrints 0]

I have been searching for an answer on this for quite a few days..

I'm really at a loss what to try next to achieve a more solid print, with two different style mugs. 
Both are rendering close to the same results. 

 

My typical process: 
*Warm mug up before taping print over top*

• 400 degrees
• 180 Seconds
• Medium Pressure
  
  Mugs I am trying to print onto: (photos included)
• Cheaper mugs from Amazon
• Conde / Dyetrans "Mug11"

Paper I have tried so far 

• Texprint XPHR
• A-Sub

Print settings I've tried:

• Regular Paper - Standard Quality 
• Regular Paper - High Quality 
• Premium Matte - Standard Quality
• Premium Matte - High Quality

 

I print onto apparel, rock slates, and many other sublimated items just fine. Only mugs have been giving us troubles.. 

Any suggestions, we'd be very thankful! 
I've attached images to help show. 

[TaylordPrints 0]

I have realized that it was a lot to do with the cook time. 

Bringing the cook time down, has helped but now I am left with a faded section , the furthest away from the pressure source... 

Full pressure doesn't seem to make any changes and so far, I've gone through 12 mugs trying to solve this. 

[Wildgoose 4,200]

I think the guys who have the most success on the mugs use the cactus wraps rather than a mug press. Different way to go about the whole thing but evidently more controlled heat and pressure.

[Dakotagrafx 7,298]

I’ve done hundreds of mugs with cactus wraps, the 6+ mug presses I tried ( including 3 knight) all had the same weakness, the area around the handle and bottom would wick heat away causing problems in those areas.  With the CW’s the bottom and handle are heated to the same temp as the rest of the mug and no problems.   And before someone ask, there is a difference in cheaper wraps to the cactus wraps that have 2 different material for pressure and to control stretch.