Just for a change, I've made something not 12th C based.
But to be honest it's mainly because I have no evidence of what was used in the 12th Century as aprons, and I was a little inspired by some early 15th Century pictures I'd seen.
Here's a butcher and another trader (baker?) from the picture. The manuscript is a few added pages to a copy of Romance of Alexander, it's actually "Marco Polo, Li Livres du Graunt Caam, in French prose, with miniatures by Johannes and his school."England c. 1400 (MS. Bodl. 264). To see more (but not higher resolution unfortunately - these are really small): from the bodlein library index page select view all, and scroll down to folio 218 recto. Zoom in to the marketplace (big red blob on the left) and see the aprons worn by the traders in context, with the 3rd trader in an apron (partly concealed) too.
On reflection (I didn't have the pictures with me when constructing this) I think mine is much too large compared to the illustrations, but it does work quite nicely. There's a better reconstruction on the medcos forum. It's also possible these aprons don't have ties on them, that they simple sit under the belt. Somethign about the way the fabric gathers up a little suggests this to me.
If you are interested in apron designs in general, may I recommend karen larsdatter's aprons links page. You'll notice that nearly all the aprons are styles that are tied around the waist with nothing above the waist, but if you check out her blacksmith's aprons page, you'll find a few aprons like this, namely:
- Nature at her forge, Roman de la Rose (Bibl. Sainte-Geneviève, MS 1126, fol. 115), c. 1350-1360
So making this up out of nowhere, here's the experimental cutting plan I tried:
The pattern is quite simple - square (as in equal length all sides) of fabric and some ties. The ties could be strips of fabric or something firmer (that needs no sewing) like twill tape. My ties are about 1m long each - mainly because this is the width of the fabric I had available. They are more than long enough for this job, but not so long they tangle or drag on the ground.
I've used letters rather than numbers for the measurements because I think of how I made this apron as a method, rather than a pattern - like T-tunics, I prefer to craft things to the wearers measurements. So measurement A is the width of material I had handy, in this case 105cm, the width I cut my square to. I then turned my square around 45 degrees until it resembled a diamond, and pinned one of the corners high on my chest (just below where I pin my keyhole necklines closed) using a pennanular broach. I marked out where just above my waist sat on this rectangle (B - 40cm for me). This is the point where I attached the ties, simply sewing them to the edges of the fabric at this point. The last step was to trim off the bottom point of the diamond. I chose to try my apron on, and get a friend to mark out my desired apron length (slightly longer than the sides, but shorter than my ankle length dress) with a pin in the centre (length C). I then turned this into a pleasing curve to cut off.
Because this was experimental and made the night before leaving for rowany festival (our big camping event), I didn't bother to neaten the edges, hem or in any way finish this garment, and hardly anyone noticed. The lack of finishing didn't detract from the garment's usefullness. Now that it has been washed, it is starting to fray, and i must choose to finish the edges or make a new one (maybe even to annother design). I say this because others may wish to quickly make an apron at some stage, or to make enough aprons for helpers at an event, and this seems a fairly quick way to make disposable aprons. Of course I'm sure that that isn't the medieval approach - they would have carefully finished edges to ensure the durability of the garment.