Ink jet ink compositions for digital manufacturing of transparent objects

A process for printing a three-dimensional article comprising:

• providing a curable ink comprising at least one monomer, oligomer, or prepolymer;
• an optional photoinitiator;
• an optional colorant;
• and a low molecular weight amide gellant having a molecular weight of from about 800 to about 2,500 g/mole;
• wherein the ink has an onset of gelation defined by the glass transition of the low molecular weight amide gellant according to the relationship Onset of Gelation (K)=(Constant) Tg of gellant (K);
• wherein the Constant is less than 1.5;
• and wherein the ink is wax-free;
• depositing the curable ink in one or more layers;
• and
• curing the deposited ink to form the three-dimensional object, wherein the cured three-dimensional object is clear.

A curable ink comprising:

• at least one monomer, oligomer, or prepolymer;
• an optional photoinitiator;
• an optional colorant;
• and
• a low molecular weight amide gellant having a molecular weight of from about 800 to about 2,500 g/mole;
• wherein the ink has an onset of gelation defined by the glass transition of the low molecular weight amide gellant according to the relationship
• Onset of Gelation (K)=(Constant) Tg of gellant (K);
• wherein the Constant is less than 1.5;
• wherein the low molecular weight amide gellant exhibits a three stage gelation profile;
• wherein the ink cures to produce a clear object;
• and
• wherein the ink is wax-free.