Rory, I probably haven't explained this very well. The 15 cm of "collar canvas" that came with the coat package was labelled T5012, but it was actually T5298, so from your last comment it is not suitable for the coat that I am making. The 1 metre that I subsequently ordered is labelled T5012. The website shows this as one of three collar canvasses. T5012 is only avialbale in drab, but T5013 is available in drab or in white. All are labelled as 'Linen Collar canvas'. The website does not indicate the difference between T5012 and T5013, or indiate what garments they should be used for. I am still unsure whther the T5012 is the correct collare canvas for the coat that I am making, or should it have been T5013? Do you know for what the two collar canvasses are best used for? What do you order for the suit coats that you make? It appears that the collar that I made with the T5298 is wrong, so I will have to do that step again, but I only want to do it with the correct material.
I will DM you on instagram with photos of the two fabrics that I have.
Some pictures of my progress with this project can be seen on my Instagram 'renrenoir'.