Here are some companies and stores in Istanbul where you can find door fly screens:

1. Koçtaş

• Services: Various home improvement products, including door fly screens.

1. Tekzen

• Services: Home and garden products, including insect screens for doors and windows.

1. Pratik Stor

• Services: Customizable fly screens for doors and windows.

1. Decoshield

• Services: Insect screens and shading systems.

1. Mosquifree

• Services: Specialized in insect screens for doors and windows.

These companies offer a variety of fly screens to fit different door types and sizes. You can check their websites or visit their stores in Istanbul for more options and details.