The large majority of french doors that we install have screens. This is because the most popular sizes are 6′-7′ wide and most patio doors in the UK are 3′-6′ wide, so there is a significant gap at one side of the doors if you try to get a screen for them.  The standard width of our double and triple glazed windows, which we use for screens in these situations, is 130mm. We can probably also find a wider screen if you want it but we usually use galvanized steel frames on french doors so they can’t be made narrower.