Best Medium for thining GW Washes - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

I'm looking to thin a GW Wash Drakenhof Nightshade by about 50% and I know that at that level water will not give a great result. Can anyone recommend a good thinner. I currently have: GW Lahmian Medium Vallejo Airbrush Flow Improver Vallejo Matt Medium Vallejo Thinner Medium Liquitex Airbrush Me

New to weathering - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

Help with Bronze - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

New to weathering - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

Black soil basing? - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

Best Medium for thining GW Washes - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

Leadbelcher Spray Acting Oddly with Shades? - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

Sand flock tips (Black sands of Isstvan V) - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

Very Happy With How The Transfers Came Out, Could Do With, 40% OFF

Initial Contrast Experiments (from us all) - Page 6 - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

New painter having trouble shading/washing brightly-colored Space Marines - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword

Magenta Red - Oh where art thou! - + GENERAL PCA QUESTIONS + - The Bolter and Chainsword