In this research, three different techniques for melt impregnation of glass fiber bundles with polyamide 12 are assessed with the aim of creating a high strength and modulus material suitable for extrusion based additive manufacturing. Impregnation quality of three production techniques: Pultrusion, PassivePin, and ActivePin were analyzed using three methods: matrix material mass fraction (M-m) determination, scanning electron microscopy of composite fracture surfaces and optical microscopy of polished composite cross sections. Pultrusion material has an overall poor impregnation degree (D-i) and fiber distribution and dispersion, the specimens lack mechanical strength and show fiber pull-out due to the excessive voids in the matrix. The PassivePin material has a significantly higher D-i and a better fiber distribution, which results in less voids in the matrix and limited fiber pull-out. Finally, the ActivePin material scores significantly higher in D-i and shows an excellent fiber distribution. As a consequence, very limited voids are observed and an even fracture surface without fiber pull-out is obtained. It is concluded that the ActivePin technique would be a great choice for application in an extrusion-based AM process, this method could allow for production of high strength and stiffness objects. POLYM. ENG. SCI., 58:601-608, 2018. (c) 2017 Society of Plastics Engineers