Which is better, block or piece fusing?

Vesta writes:

Now that I’m making markers for folks, I am cogitating deeply about block fusing. You said:

“Making a separate marker for block fusing and then to have to spread it as a separate operation seems more costly to me.”

But the alternative is to lay and cut a fusible marker, and that seems to balance out the separate lay and cut of a block fused marker. But then if you add in the extra work of matching and fusing each pattern piece, it seems like block fusing wins. Am I missing something?

I’m searching the blog for a whole post devoted to fusing. Not finding it. I’m shocked, Kathleen. Or I’m inept. One or the other. :-)


I’ve published many posts related to fusing -that link doesn’t include the fusing map entries. But more to your point, I started a series on continuous fusing machines nearly 8 years ago but dropped the project as it didn’t seem that anyone was interested. Not ready to give up so quickly, I wrote another post reviewing the equipment we saw at the SPESA show in 2007. Three years later, I wrote How to apply interfacing (in a commercial environment) which provided still more detail. But anyway, I’m glad to know there is more interest at this late date.

There are many variables to determine which is more cost effective so that is probably the first discussion. Some of these variables are cost, product type (design features) factory equipment and lastly, the experience, practices and competence of whoever is doing the cut and sew.

  1. Block fusing uses more fabric than per piece fusing. The marker in the What is block fusing? post shows the marker with a fusing block to be 5 inches longer than the marker which has facings piece fused. So maybe you do a cost benefit analysis and decide that losing 5″ off of each ply is acceptable? There is still more to it.
  2. The product’s design must be congruent with block fusing -and many aren’t. For example, if you have lapels (front facings) or collars that need to be fused and all of your goods are not from the same dye lot, you could be in a world of hurt  -depending on the remaining variables (see below).
  3. The experience and practices of whoever is doing cut and sew is critical when block fusing -particularly spreads that have more than one dye lot. For example, almost nobody labels their cuts these days.  I’d broached this subject nearly 10 years ago, but nobody was interested, wah. There’s more in the entries on batching but then this entry would become so link intensive that nobody would read it. Suffice to say, I wrote about these factors quite a bit early on.

But I digress: if the plies of the spread are not carefully matched to align to the plies of the block fuse spread, it’s going to be a disaster. Who knows which ply layer will be paired with the pieces of the main cut? And if you need to match a stripe or plaid (again, across a turned back lapel)? I’d forget it. The most cost effective ways to manage that is with first and second cuts but then you need special pattern pieces for those too. To make the second cuts, you wouldn’t necessarily need a die cutter but could use a band saw or even a knife with clamps.

  1. At last we come to equipment available at the sewing factory -which reminds me, who benefits most from block fusing? I suspect block fusing became popular because it was more convenient for smaller shops who didn’t have the power requirements to run fusing equipment -or the money to buy the equipment. Having stuff fused by someone else who had the equipment was a godsend. After awhile, particularly in areas with heavy emphasis on sportswear, people became habituated to the practice of block fusing and didn’t realize there were other alternatives.

In summary: If your fabric price is relatively low and the cost of labor is (all things remaining equal) more costly AND there are no match stripes, no match plaids and you can cut from the same dye lot, AND you’re not making high end goods, then go wild. Block fuse. However, if you’re making contemporary, bridge or designer apparel, particularly with spot fusing, then block fusing probably isn’t a choice.

There is an extended conversation about block fusing in the forum if anyone else is interested. There are also links to resources of providers who can fuse rolled yardage.

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  1. Vesta says:

    Yay! Thank you. I spent a chunk of time today reading blog and forum posts. I posted a great video of block fusing a roll of fabric. Geek. Out.

  2. Vesta says:

    I commented yesterday, but it got eaten.

    Yay! Thank you! I read everything in the blog and forum that I could find yesterday on the topic. This is exactly what I was looking for.

    Here’s what I’m finding: the only way for me to make the best marker is to talk with the contractor who will be cutting, and maybe even the sewing contractor. How do you like button holes marked; do you block fuse; how do you handle shading; HOW LONG IS YOUR CUTTING TABLE; what kind of marker do you like (a remarkable number don’t like mixed sizes, or not *too* mixed); do you have a cloth drill (a local shop here doesn’t); etcetera, etcetera, etcetera. The designers we work with generally have no idea what I need to know. For instance, I got a call from a designer *after* the marker and fabric had been delivered to the contractor saying “Oh, I forgot to mention that I want the stripes running horizontally across the garment.” The problems really started way before that, when she wouldn’t get me any fabric information that I asked for. So I never even knew there was a stripe in the mix. I had to remake the marker, for which I charged. She wasn’t pleased, but fortunately it wasn’t much. Much less expensive than getting 50 pieces of a product that she hates, then probably blaming it on us.

    Anyway, I digress.

    I posted a great video in the forum of a roll of fabric being block fused. Well, great if you are an apparel manufacturing geek. Which, if you’re reading this, make friends with that.

  3. Kathleen says:

    Your comment got held for moderation (for some strange reason) and I haven’t logged in to approve it. The power is out so it will be awhile.

    Many of the things you mention are actually in the book I wrote if you can still find your copy. See the marker making section. Too bad your customers haven’t read it, it would save a lot of time and money.

  4. Kathleen says:

    You might also read posts on this site about markers. The one on fabric inspection at the factory is exactly what you’re describing. I cannot get the link just now but again, I write this stuff for customers.

  5. Vesta says:

    Yeah, I reread a bunch of sections of the book last week. I also searched and read the blog about markers. I think sometimes that there is so much information here and there in posts that it can be hard (for me, anyway) to get my arms around it without hashing it out, specifically.

    No need to release the prior comment. It would be redundant.

  6. This VERY IMPORTANT FACTOR may have been mentioned in a previous entry but I don’t see it here:
    If the fusible interfacing shrinks at a different rate (from heat exposure) than the fabric being fused then we most certainly BLOCKFUSE AS MUCH AS POSSIBLE to avoid ending up with pieces that either don’t fit the garment anymore or fabric pieces that shrink more than interfacing and interfere with the fusing process (leaving air pockets)

  7. Vesta says:

    Ack. Interfacing shrinkage. (There’s a big thread in the forum about interfacing shrinkage that I read yesterday, BTW.) Few of the designers we come across give interfacing more than a glancing thought. I’ve even had someone tell me, after having produced her product for years, that it had no interfacing, yet I was staring at the pattern, which had plenty. As it turns out, so did the product, but she just didn’t understand how her product was put together. All of which is to say, unless I am spec’ing the interfacing, I don’t often have enough information to know if or how it will shrink! So, now I want to talk to the cutter, sewing contractor, AND the interfacing supplier before making a marker. Whee!

    Rocio, we (my pattern maker and I) think about your work methodology all the time. If we didn’t produce the pattern and don’t have our hands on the fabrics and parts, we just don’t feel like we can do our best work. There’s a lot of leg work to do when you inherit patterns and products, just to get up to speed and make sure there aren’t any problems hiding in there that might blow back on us.

  8. One factor I also consider, when deciding whether to block fuse, is whether the fabric is going to “go wonky” on me. If the piece is bias-y, stretchy, flimsy, or otherwise troublesome, fusing ahead gets it under control and is more effective and efficient than trying to reshape it for fusing after it’s cut. I’m in the business of samples and small runs, so sacrificing a few inches of fabric for my time and heartache makes sense.

  9. Marsha says:

    In a workshop/up-to-10-people shop setting, I believe choosing on whether to block-fuse or piece-fuse would depend on the labour cost of handling cut pieces of fabric vs the labour cost of partial-fusing, laying out and cutting the partial fused fabric pieces.

    The partial fusing marker image gives me new ideas on how to manage my workflow! Also on #2 of your article. I am currently on minuscule production runs so it will be an issue I need to address once the scale gets bigger it requires cutting across dye lots. Thank you Kathleen.

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