plain — simple, without decoration or pattern

a young woman holds up a completely plain white t-shirt with no patterns, prints, or decorations. Her friend stands beside her holding a brightly patterned shirt covered in flowers, stripes, and colorful designs. The plain shirt appears simple and basic compared to the ornate, decorated alternative. Other shoppers in the background examine clothing with various prints and embellishments. The friend points at both shirts to highlight the obvious difference in styling. something that is simple and without decoration or pattern