There are 4 card profiles that we use. Have your horse standing straight and square looking forward.
We start by finding the Scapula which is the big shoulder blade. Sometimes on a stouter horse you will have to push with the flat of your hand fairly hard. Find the back edge of the scapula and either use chalk or a peace of light colored tape at this location go all the way over the horses spine to the other side and make sure it is in the same location on the other side, this location will be A. Now go about 2″ behind A and place another peace of tape or chalk line this will be A1. Again move about 2″ behind A1 or 4″ behind A and place another peace of tape or line this will be A2. Now find the low point of the back, Approximately 8″ behind A and place a peace of tape you can mark this location B. You can take that one step further and mark a location 2″ behind B and place another line or peace of tape call this location B1. Now go about 8″ behind B and place another peace of tape or line and call this location C.
Now go back to A and get the A cards. Find the profile that most closely matches the card profiles. A is the best place to start but if you have to for a really wide muttony horse can use any of the cards that are closest. Do the same for A1 and A2. Notice int the picture below that there are no gaps either on the side or in the middle. This is the best card for this horse. If you are not sure and find another card that is close go ahead and take pictures and send that also.
I want to make a note here that it is very helpful to take pictures of the cards on the horse, that way I can check to make sure you are on the right track. We can even go a step further and make a video but I find pictures to be really effective. I like pictures from the side, from the front looking back over the shoulder to the opposite hip. Looking forward over the hip back to the opposite shoulder, one last picture is very helpful is from the back at the hip looking forward over the spine to the withers.
Now move to B and get the B cards here again find the card that closest fit. If you have to use a C card go ahead and use the closest fitting card. Here again pictures are helpful. Now move to your B1 mark and find the right card for that profile. They also give me the correct card numbers to use.
Now move to C and get the C cards here again find the card that closest fit. If you have to use a C card go ahead and use the closest fitting card. Here again pictures are helpful.
We are going to use the cards for the rock in the horses back. These are the long cards marked R3, R6, R9, and R12. If you want to make it easier you can take a chalk line or tape and place it about 4″ below the topline of the wither and again about 4″ below the topline at C.
We want to start by placing the card on the horses back in a perpendicular fashion. Locate the notch at the B location on the card and place that on the tape or line on the horse at B. It is important that the edge of the card is perpendicular as would be with the bar of the tree and the way it fits the horse. A should be to the front and C to the back.
Now find the card that has the contact with the horse. you want to have as little gap as possible either in the front or in the middle at B. R3 has the less rock and R12 has the most.
Now we are going to note another measurement and that is called S and that is the location of the scapula on the rock card. Note that it has lines with 6, 6 1/2, 7, 7 1/2, 8 and 8 1/2. So in this case this horse is actually a 9.
We are almost finished but we would like to take one more measurement and that is the distance from A the point just behind the scapula to the hip. This measurement will help determine the length of skirt. We call this AH
Here is the link to rent the Dennis Lane Profile Cards.