Finally I found a moment to write some notes about how to string a top down/bottom up roman shade. A few readers have asked me questions about this and there don't seem to be any good tips online. Besides, I need to jot this down so I don't forget myself!
This illustration I just made doesn't read as clear as I thought it would. The orange lines represent the cords that lower the top down. The gold lines are the ones that pull the bottom up. Green dots are where you would put the lift rings for the top down cord. Blue dots are lift rings for bottom up cord.
To measure the amount of cord you need.
Use this diagram when measuring the length of cord needed for your shade. Measure cord after you have sewn on the lift rings.
For the cord that pulls the bottom up: run cord from the lowest lift ring up to the top of the shade, then across the top to the right upper corner of shade, then extend the cord as long as you would like to have it hanging when the shade is fully lowered. Repeat this step with any additional cording you will need (the wider the shade, the more rows of cord you will need). The cord will be shorter the closer the row of lift rings is to the left edge of the shade, because it does not need to travel as far across the top of the shade.
To measure the cord that lowers the top up and down: Run cord from the very top lift rings that will only attach to the top down cords. Then run the cord across the top of the shade to the upper left corner. Extend the cord all the way down to the bottom of the shade, then for the additional length that you want your cord to dangle when the top of your shade is fully lowered. Repeat this step with any additional cording you will need (the wider the shade, the more rows of cord you will need). The cord will be shorter the closer the row of lift rings is to the left edge of the shade, because it does not need to travel as far across the top of the shade.
Of course, you can choose which side you would like to have your cord handle run out from the shade. For this tutorial, I have the top down cords running out to the left and the bottom up cords running out to the right. Another thing to remember: this diagram shows the back of the shade. Once the shade is mounted. The cords that lift the top down will hang on the right side and, you guessed it, the cords that lift the bottom of the shade will hang on the left side.
To string the shade.
For bottom up cords: Knot the end of cord to the lowest lift ring. Run the cord up through the lift rings directly above the bottom lift ring. Do not run it through the very top lift ring (the green ones in the diagram). You will then run the cord through the pulleys that were drilled into the mounting board. One row will be for the bottom up cords, the other is for the top down cords. Continue running the cord across the mounting board pulleys and then through the cord lock (if you are using one). Running string through a cord lock takes a little practice. I'll try and get more details up about that later.
Continue stringing the other rows the same way. All cords should run through the same pulleys and cord lock. Once all your cords have been run through, you can attach a cord handle and knot the cords so the handle stays in place.
You may find it easier to run the cords through the pulleys and cord lock after you have drilled the mounting board onto the window, but I prefer to do it while everything is laying down flat on the floor or table.
For the top down cords: Knot the end of the cord to those lift rings at the very top of the shade (marked green on the diagram). The lift rings should be sewn on securely just below the top seam of the stiffener board. Run them through the other set of pulleys and cord lock just as you did with the bottom up cords. Attach the cord handle just as you did with the other set of cords.
Hope this helps some of you out!