Supaya konsisten dg 'trade mark' = 'merek dagang,' saya mengusulkan 'trade dress' = 'desain dagang.'

Sebelumnya, saya ingin menggunakan 'trade dress' = 'desain produk,' tapi karena yg diperdagangkan ada dua macam - produk/barang dan jasa - maka saya cenderung memilih alternatif di atas. Kalau 'desain produk' kan hanya merujuk pada produk; untuk merujuk pada jasa harus digunakan 'desain jasa.'

Jadi, 'desain dagang' sudah merangkum keduanya - desain barang dan desain jasa.

Berikut referensinya:
(Product design) Trade dress consists of the variety of elements in which a product is packaged or a service is presented. ...
www.marklaw.com/trademark-glossary/T-Z.htm

The distinctive packaging or design of a product that promotes the product and distinguishes it from other products in the marketplace -- for example, the shape of Frangelico liqueur bottles. ...
www.leanlegal.com/dictionary/t.asp

[trademark]. The totality of elements in which a product or service is packaged or presented, such as the shape and appearance of a product or container, or the cover of a book or magazine. ...
www.bemafashion.com/Default.aspx

Trade dress refers to characteristics of the visual appearance of a product or its packaging (or even the facade of a building such as a restaurant) that may be registered and protected from being used by competitors in the manner of a trademark. ...
en.wikipedia.org/wiki/Trade dress