Filigree in Portugal, as previously mentioned, was ancestrally and primarily linked to the northern region of the country and, at least since the 18th/19th century, to two specific production centers, namely Gondomar and Póvoa de Lanhoso. Thus, it is the characteristics of these centers, which have established themselves over time (closely associated with so-called popular goldsmithing) and have spread through other regions to the rest of the country, that are unanimously accepted and recognized as the traditional typology of Portuguese filigree.

Although the artisanal technique of filigree is the same, these two centers coexisted in the past with similar characteristics and are traditionally distinguished only by the type of pieces produced. And although in Póvoa de Lanhoso almost exclusively gold was worked, with very elaborate filigree of a more open mesh, relatively wide, with a slightly thicker wire, and in Gondomar silver has always taken precedence (with a finer and lighter mesh, tighter mesh), nowadays the differences have blurred over time, resulting in work that is virtually identical. The pieces themselves remain more closely tied to the tradition of one center or the other, but are produced indiscriminately (including collaborations between workshops, goldsmiths, and filigree decorators from both production centers), so today we cannot distinguish production except by the work of each filigree goldsmith and their specific personal characteristics and the unique stamp they give to their production.

Nowadays, silver is worked more (with some exceptions), in pieces that remain white with the color of the metal used or that are plated to acquire different colors and shines (gold plating and rhodium plating, for example). Some filigree makers enrich and diversify their pieces with colored stones, enamel applications, and pearls.

The wire used by filigree makers varies in thickness. For certification purposes, the maximum thickness of the wires (whether gold or silver) must be 0.22mm. The wires used in Filigrana de Portugal are twisted in pairs and then flattened.

Large pieces (over 500 grams) that are 100% filigree may use thicker wire (adjusted to the size of the piece and the space to be filled). However, the certification of these pieces will depend on individual and specific evaluation.

However, filigree owes almost all its value to the work of the 'enchedeira', the artisan who decorates the piece, filling the frame or skeleton (manually or using technology or mechanical means and aesthetically and technically the responsibility of the goldsmith) with complete freedom and mastery (even within the decorative grammar particular to Portuguese filigree). This work, which was traditionally and in Gondomar exclusively done by women at home, is now, and increasingly, ensured by workshops, with the question of gender in this task fading. In Póvoa de Lanhoso, this work has always been, and still is, one of the production process steps carried out in the workshop, preferably by women (but also, and more sporadically, by men).

Regarding the decorative grammar present in Filigrana de Portugal, as previously addressed, it is based on traditional shapes and motifs freely combined, although nowadays, in many cases, with a contemporary aesthetic detached from traditionalist canons. Nevertheless, the essential typology of Filigrana de Portugal must be present, as it is this particularity that distinguishes and differentiates the filigree made in Portugal from that made elsewhere in the world. These characteristics are: the wire that fills the pieces is twisted, flattened, and tapered so that it coils in SS, spirals, and in 'rodilhões' (Póvoa de Lanhoso) or 'crespos' (Gondomar), scales, curls, snail shells, and cornucopias. The decorative motifs are always sinuous, with no right angles, in a constant of curvilinear movements.

As previously mentioned, for a piece to be certified as “Filigrana de Portugal” it must fit into one of three categories:

- 100% Filigree – for pieces entirely handmade, from their base (drawing the wire, framework) to the finishing. It is used mainly (but not exclusively) in pieces of more traditional typology.

- Filigree – for pieces with more than 50% incorporation of this artisanal technique in their visible area and whose supporting materials are also precious metals (gold and/or silver). It is mainly used for personal adornment pieces (but not exclusively).

- Filigree Application – for pieces that incorporate elements fully made using the filigree artisanal technique (100%), but whose supporting materials and/or other techniques used also incorporate materials other than those traditionally used in filigree work (solid gold or silver or other metals, textiles, cork, wood, etc).

This information will be present on the piece through a certification label, and the hallmark will attest on the piece itself the “Filigrana de Portugal” mark and the quality and authenticity of the metal alloy.

_{Source: Ramos, Graça, Specification Book for Certification, 2017}