Just had to post this. It’s an old favourite…

Papier Mache Paste

½  cup flour

3 ¼ cups water

large jar with cover

½ cup sugar

1 teaspoon salt

½ teaspoon lime juice

Put 1 cup cold water in jar and add ½ cup flour. Cover and shake until well-blended. Pour into saucepan and add remaining 2 ¼ c. water, sugar, salt, and lime juice. Mix thoroughly, and heat, stirring often. Let mixture come to gentle boil and boil for 30 seconds. Remove from heat and cool before using. Cover. It will store for a few days, but stir before each use.