Question: what type of paper is used for oil painting
[{'answer': 'canvas', 'provenance': [{'wikipedia_id': '22605', 'title': 'Oil painting', 'start_paragraph_id': 5, 'start_character': 95, 'end_paragraph_id': 5, 'end_character': 101, 'bleu_score': 1.0, 'section': 'Section::::Techniques.\n'}]}, {'provenance': [{'wikipedia_id': '22605', 'title': 'Oil painting', 'start_paragraph_id': 18, 'start_character': 0, 'end_paragraph_id': 18, 'end_character': 434, 'bleu_score': 0.9712154609069981, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10783817142979714359}, 'section': 'Section::::Supports for oil painting.\n'}]}]