The size of this backpack is smaller than folder or A4 paper,DOESN'T suit for storing folder or A4 paper . Nylon+Dacron.9.84 in*12.40 in*3.54 in(25 cm*31.5 cm*9 cm).Suit for 3-year-old to 6-year-old children. Backpack's backside adopt 3d thicken breathable design,disperse weight of schoolbag ,reduce strain of trapezius muscle,human engineering weight-bearing. Dual elastic side pockets,front zippered pocket , interior computer interlayer . Interior dacron lining , external bi-directional smooth zippered .Practical lash tab, thickening decompression padded shoulder straps ,reinforce accessories ,comfortable handles,large capacity and Lightweight. Promise 90-day after-sales service guarantee. Suit for 3-year-old to 6-year-old children. If you want to store folder or A4 paper ,the folder or A4 paper will have to bend at the corners to fit into the backpack. We suggest that you just store some book ,9.7in tablet,drinks,snacks,toys into this backpack at best. Because this bag is designed for little child ,not for office worker. The product's color might be slight different in the picture because of the lighting effect, please in kind prevail. Our product is not the cheapest, but it is the best. Manual measurement,there is a slight error in size probably,product in kind prevail.