Things You'll Need
Padded iron-on lining
Stiff iron-on linterfacing
Whether you are a purse-maker or just a purse carrier, you have probably experienced the frustration of a floppy purse. Lack of stiffness makes it difficult to store purses, which flop over and acquire unattractive creases, and make it more difficult to find things inside the purse. While it is easier to make a purse stiff during the initial purse creation -- by choosing stiffer fabric and otherwise constructing the purse to retain its shape well -- it is also possible to use inserts to stiffen an existing purse. Purses can also be deconstructed, built more stiffly, then put back together.
Use a heavy fabric or other material, like canvas, vinyl or leather. Test for stiffness by holding a section of the fabric up in your hand and seeing whether if flops over or retains its shape. Stiff fabrics may be more difficult to stitch on a sewing machine, but they will retain their structure much more effectively.
Construct the purse in layers. The thinnest, floppiest purses are often constructed of just one layer of fabric. Each additional layer you can include in your purse adds structure and stiffness. Include a lining of heavy or thin, starched fabric. Between the bag exterior and the lining, you can add elements like heavy-duty iron-in interfacing, which stiffens fabric, as well as padded iron-in lining, which both stiffens and adds bulk that helps purses retain their structure.
Add structure with cardboard. If you really want your bag to be stiff, sandwich pieces of cardboard barely smaller than your purse between the bag exterior and lining. This is most effective for square or rectangular bags, like small totes or clutch purses. The thicker the cardboard, generally the more stiff the bag will become.
Use a purse frame. Purse frames are generally made of plastic, metal or other stiff materials, and add structure to fabric bags. Simply cut the top of your purse to the same shape as the frame, add a strip of glue to the top of the purse and inside the frame's channel, and work the fabric into the frame. Press the fabric tightly into the frame with a pair of scissors and allow the glue to dry.
Deconstruct an existing purse or bag, and put it back together after adding layers, a stiffener, or a frame. No need to be stuck with a floppy purse, even if it wasn't handmade. Remove the lining, add padded lining or stiff interfacing or a cardboard insert, then replace the lining. Or, reshape the top of the purse, using scissors, and work it into a purse frame.
Removing excess elements can also give a purse extra stiffness. For example, even the stiffest of purses may flop over if it has too-heavy handles or lots of metal hardware. Strip down unnecessary elements, and even consider replacing heavy handles and hinges with lighter versions.