資料 and 材料: reference information and materials
Compare reference information with materials for making or cooking.
Information as a basis
資料 (しりょう) means information used for research, explanation, or judgment. 「会議の資料を読みました」 says that the speaker read the meeting materials.
「資料を集めています」 means collecting materials. They may be documents, photos, or figures, not only paper records.
Materials used to make something
材料 (ざいりょう) means materials or ingredients for making something. 「料理の材料を買いました」 says that the speaker bought cooking ingredients.
「木を材料にして箱を作りました」 means making a box using wood as the material. It relates the input material to the finished object.
The figurative basis for judgment
「判断の材料が足りません」 means lacking enough information for a judgment. 材料 here refers to information, not physical wood or food.
Reference 資料 can serve as 材料 for judgment, but 「料理の資料」 is reference information about cooking, not automatically ingredients. Read the modifier and intended use together.
How do you say there are not enough cooking ingredients?
Show the answer and why
Say 「料理の材料が足りません」. A shortage of documents explaining cooking methods would instead concern 資料.