[Battosai]

Are you trying to stretch them widthwise or lengthwise? If widthwise, ive had good luck with these

My problem is that, depending on the trainer and design, my requirments to stretch can vary quite wildly.

I'm sometimes a size 11, 12 or 13 depending on the manufacturer, so it's often a crap-shoot when I purchase and try them on. Sometimes they need lengthening and others are really, really narrow (tend to be adidas) so I need a few shoe trees doing different jobs, I think.

How long does it generally take for the stretching to permanently take effect? Or does the material slowly reform the orignal shape if it's not continually stretched?