Haven't flown since the 3-1-1 rule has been in effect. I thought I read here some time ago that the quart size bag can't have writing on it - like "ZIPLOC"- imprinted on bag. Is this true? Does it matter if it's a sliding "zip" like Hefty or a "press down both sides together" like Ziploc? I know it sounds silly but I've checked the TSA website and it just says quart sized, clear plastic zip lock bag. I'm taking the "clear" part as not a colored plastic bag. Many thanks for your help!!