1.On a flat surface, place the 20"square of F1( fabric 1 ). Along 2 adjacent edges place the 2" strips of F 2. below that place the 4" strips of F 3. ( Where the fabric strips meet at the corner there should be ample overlap which will later form a mitred corner seam ).( photo 1 )
2. From where it is placed turn the 2" strip face down onto the 4" strip and pin. Sew this 1/4 inch seam, to join the 2 border strips.( do the other side the same ) . Press towards the narrow strip. Lay back by the big square.(also photo 1 )
3. Now pin and sew the joined borders to the 20 " F1 square ( R sides tog ) starting at the outside edge. When you get to corner stop 1/4 " from the end and backstitch. do same on other side. Press seam towards big square.( this is apron front )(photo 2 )
4. To make mitred corner seam, fold the apron front diagonally right sides together. Get completely square.( pin in a couple of places to hold straight )( photo 3 )
5.Take a ruler ( with a 45 degree angle marked ) and lay it so it continues the line of the folded fabric starting from where your seam finished on the border.( the 45 d line should be parallel with the top and bottom of your fabric ) mark this line, then pin across it in about 3 places. Sew this seam backstitching at both ends.( photo 4 )
6. Unfold apron and check your seam. If you are satisfied with it trim excess fabric to 1/4" and press the seam open. ( front now finished ).