I have OTT but not the screw in kind but they do have them. OTT makes a difference with color matching at the embroidery machine.

I have a sewing room with no daylight and I use full spectrum florescent tubes. In most of my house I have their screw in equivalent, the compact florescent bulbs which are called 'daylight' not the soft white. They are the truest to anything I can find and closest to Ott lights without the high price. Good luck.

I use really high intensity florescents, the equivalent of 100 watt incandescent bulbs or higher. They don't get hot, so they are still safe for use in a regular fixture. It's made a huge difference in the lamp I use to applique by, which is just a regular floor lamp in my living room.

Annie