I talked with Emma about my project and about the suggestions that Uli had for it. Emma thought that if the stacking function hindered the customisation of the lid, then perhaps it was not suitable for my project. I.e. the lip and/or groove of the bowl will have further affordance as it allows the user to use a cloth, towel, plate etc. to cover the bowl, and if the stacking function doesn't allow for this further affordance, it might lessen the attachment the user develops towards the product.
Emma wants me to test using a second part in the mould, to support the lip as it drys. This will hopefully stop the walls of the bowl from buckling.
Emma agreed with Uli's suggestion of using the same forms of the bowl for the dough scraper and lame, because it's a good way to unify the tools as a family. I need to move on to designing and making the scraper and lame as soon as possible, and I'd ideally like to have some models of each in time for the 'state of play' exhibition on Friday (1 week away).