This is a pattern adapted from an 1843 example in the Journal des Jeunes Personnes. This includes 2 printed copies, one for each of the right and left sides. Each collar half can be reused to make a corresponding cuff if desired. Note there are no instructions regarding how to do the embroidery itself, as there are a number of ways it can be accomplished (whitework, stumpwork, etc). There are several complete antique references in full color PDF on my Facebook Page (Elizabeth Emerson Designs). These books are free and can be adapted to this pattern. If you are needing voile there are two listings here, one for just the paper patterns or paper patterns and enough voile (washed and pressed) to complete a collar and cuffs set (you have enough that you could make a full fichu too 18" x 54")
Note that the collars pictured are similar antique versions, with a close up example of Mountmellick whitework.