Happy to share :)
The top ‘plastic looking’ part of my tissue box cake is just a scan of the entire top of the box. It’s not separate to the rest of the top of the tissue box – it’s all a single edible image. FYI – I used a craft knife to cut a slit in the centre to insert the gumpaste tissue. Have attached a photo showing the various stages in making this cake. Hope that helps.
NB. - I can’t take credit for this design – I copied the concept from Yummies – Cakes & Special Treats, Sydney