I am very new to blender so go easy on me. I have a model I want to cast in cement for this is obviously need a mould. The plan is to make this in blender and then 3D print it. I know about Boolean operations and adding a cube around my model and subtracting the model. The problem here is however that such a mould becomes very big wastes a lot of plastic and takes a long time to print. What I want instead is a mould that is let's say 5 mm thick everywhere. Is there a good way to make this (note that simply scaling will not work if the model is not convex)?
I have had some success with sculpting and using different tools there to make a larger (almost) copy of my model and then subtracting the original model from this (see picture). But this results in a model of uneven thickness and is quite time consuming and imprecise. Is there a better way?
Thanks in advance!