In preparation for a soon to follow post, comes this glossary entry on block fusing. Block fusing is the practice of applying interfacing -edge to edge- onto yardage before the pattern pieces are cut out of the fabric.
There are two basic types of block fusing, mostly based on the needed quantity. If your cut is large and you need yardage fused, you could send your fabric off to a service who would do that for you. Stand alone fusing services will often provide fusible too so you wouldn’t need to source that separately.
The other type of block fusing is done for smaller quantities. The way this is done is to block off an area in the marker into which the fused pieces would fit. After fusing, the fused fabric is re-laid and then the pattern pieces are cut from it. At top left is an image of a marker with a fusing block off to the left. The bottom marker doesn’t have a fusing block.
Once the marker is cut and the block area is set aside and fused as one piece, the plies from the fusing block are re-stacked and the pattern pieces are cut. In this way, there is no fusing needed after the fact.
As to whether block fusing is preferable to piece fusing is subject to debate -and the next post.