Stable income: Somewhat stable

Print-on-demand is a popular side hustle where individuals create custom designs for products like t-shirts and mugs, with costs ranging from $0 to $100 for design tools and marketing. Based on online research and experiences, it can provide a moderately stable monthly income. While some sellers have consistent earnings, there can be fluctuations due to market trends and competition. Overall, it offers decent predictability for income, but there may be variability month to month.