While creating the templates for your products, the admin can lock the specific object from the backend. It will restrict the customer to edit any object or the particular area.
Admin will get the lock feature in the layer management section, after adding the element to the product. With this feature, you will have full control over the customization of any product. For the text object, customers can only change the text of the object but not the text. For Image, customers can only change the image. However, they will not be able to apply effects.
Note: Lock feature is an add-on feature.