Old Reformed theology, like that found in Franciscus Junius and Amandus Polanus, often referred to two prongs of theology; i.e. archetypal and ectypal theology. Rinse Reeling Brouwer defines what this entails for us:
Archetypal’ theology is the theology of the essential and uncreated knowledge that God has of Himself. ‘Ectypal’ theology is communicated first of all to the human nature of Christ, to the angels, and to the saints in heaven. In its higher forms it can be known by way of intuition ; the multitude of forms can be conceived uno simplici actu, in one simple act. But as long as man wanders on earth (‘theologia ectypa’ as ‘our theology’) and is not yet in his heavenly homeland, he – being subject to a lower form of ‘ectypal’ theology – must reconcile himself to the limits of his faculties as an intellectual creature, that is, of his discursive mind….
I think this is a helpful distinction in that it highlights the idea that God in himself (in se) remains ineffable. Even if what has been revealed of God in Jesus Christ is, in the economy of God’s Self-revelation is an exacting reference to the God who just is in eternity – eternally as Father, Son, and Holy Spirit – there remains an antecedent reality of God that remains impenetrable to our constantly growing minds and hearts; growing, that is, in the grace and knowledge of Jesus Christ. So while there is an exact correlation between God theologically and economically, there remains an aspect of this reality that lets us know that we are up against an ultimate that is not of our making. The God we see in Jesus Christ is exactly the God who has always eternally been, but we can only approach this God in ectypal ways that will always remain ‘provisional’ modes towards knowing God. In other words we walk by faith not by sight.
 Rinse H Reeling Brouwer, Karl Barth and Post-Reformed Orthodoxy (Farnham: Ashgate Publishing Limited, 2015), 60.
As corollary to this archetypal/ectypal distinction one point I didn’t hit on, is that ectypal knowledge of God will always be the provenance of us, His creatures. That even in beatific vision our knowledge of God, while in exacting correspondence to who He is, as revealed in and through the Mediator, Jesus Christ, will always be less than His own archetypal knowledge of Himself since He is God and we are not. So underneath this distinction between the ‘knowledges’ there is the premise of the Creator/creature distinction. While fully participating in God’s triune life as adopted children of God, as ‘sons of God’ we have access to God by Grace and not by Nature; as such our knowledge of God will always be less than what His Self-knowledge is. He is God we are not, this is really the basis upon which archetypal and ectypal distinctions turn.