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Post-printing processes are necessary for binder jet printed parts to increase key properties in materials such as density , but the full effects of this post-processing are not yet well understood .
 concept or principle: processes; material: binder; concept or principle: properties; concept or principle: materials; material: as; concept or principle: post-processing
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
 Entities: processes, binder, properties, materials, as, post-processing 
Answer:
 concept or principle: processes; material: binder; concept or principle: properties; concept or principle: materials; material: as; concept or principle: post-processing