3d printed material having color and/or reflectivity control

Abstract

The invention provides a method for producing a 3D item () by means of fused deposition modelling using a fused deposition modeling 3D printer () comprising a printer nozzle (), wherein the 3D item () comprises one or more layers () of 3D printed material (), the method comprising a 3D printing stage comprising: —providing 3D printable material () to the printer nozzle (), wherein: —the 3D printable material () comprises 3D printable core material () and 3D printable first shell material (); —the 3D printable core material () comprises a core thermoplastic material () having a core thermoplastic material melting temperature T; —the 3D printable first shell material () comprises a first shell thermoplastic material () having a first shell thermoplastic material melting temperature T; wherein T>T; —the 3D printable first shell material () has a 3D printable first shell material optical property, the 3D printable core material () has a 3D printable core material optical property different from said 3D printable first shell material optical property; —controlling a temperature Tof the 3D printable material () in the printer nozzle () according to a scheme wherein during a first time period t: T>T>Tapplies and wherein during a second time period: T>Tapplies.