What's the biggest projection you can get with butt implants placed subfascially?

Buttock implants can be custom made to just about any size and shape too. The limiting factor is the anatomic dimensions of the individual patient. Larger buttock dimensions both vertically and horizontally can accept a larger implant - possible providing "10 cm projection" . Indeed larger implants can be placed subfascially but with more potential problems in the long run, such as: more visible implant borders, more palpable implant, more... more

You probably could get a 10 cm projection if you used a custom implant, but I would not advise that. That size implant is associated with a high risk of complications. Although you can place a larger butt implant subfascially, in my experience, submuscular is the better approach because there seem to be fewer complications. It will be hard for you to safely achieve the dramatic result you are seeking.