8563
Firstly , an alternative method of filament positioning in material extrusion is proposed , referred to as the ‘ offset method ’ , which aims to reduce the volume of empty cavities between deposited material .
 filament, material extrusion, as, offset, volume, material
Please list all entity words in the text that fit the category. Output format is "word1, 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} 
Answer:
 filament, material extrusion, as, offset, volume, material