Picture jigsaw puzzles, with kerf eliminated, snugly fitting

Made on a Glowforge
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My own opinion is that picture jigsaws are more fun when the pieces fit nicely, without wiggle, without visible gaps, and allowing sections of puzzles to be easily picked up and rearranged.

The good news is that it can be done. Here’s one with cuts adjusted for kerf, snugly fitting for easy handling, as the video shows. It’s made of matte photo prints mounted on 1/16" plywood.

Obviously, the kerf adjustment can be tuned to give the desired level of snugness or looseness. This one is snug enough to stand up by itself, if bent into a slight curve:

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The only way to adjust for kerf is to cut the pieces individually. The above 24"x19" puzzle was cut from 12 letter-size sheets of individual pieces:

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For it to appear seamless, the alignment has to be accurate to around 0.2mm (depending on the photo and the pieces). The three pieces shown below were actually cut from different sheets:

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Additionally, it’s cut upside-down, so that there’s zero kerf on the printed side (the wider part of the kerf is on the back).

It’s hard to tell from the photo, but the cut lines are much less noticeable than in puzzles cut the ordinary way. On the darker areas they pretty much disappear.

The bad news is that I haven’t figured out how to make the process more efficient. For small puzzles it’s not bad. For a larger puzzle like this, cut from 12 letter-size sheets, it takes me a few hours and at least $70 to make one copy.

The labor cost is partly due to deliberate tradeoffs, choosing quality of appearance over efficiency, especially:

  1. Cutting upside down, for reduced visible kerf. This makes masking essential.

  2. Using home inkjet photo paper, instead of lab-printed photos, because the edges are less noticeable on that paper. Then you need to use the right kind of photo paper, or else worry about tearing the photo when you remove the masking.

The materials cost mostly comes from:

  1. Photo print: $1.30 per sheet
  2. 8x12x1/16" Basswood plywood: $2 per sheet
  3. Adhesive sheets (incl. extra used for demasking): $1.30 per sheet
  4. Depreciation on Glowforge & air filter: $1 per sheet (is that a reasonable guess?)

I’m working on a tutorial, but my guess is that most people won’t find it worth the effort, except those (like me) who have a pet peeve about sloppily-fitting laser jigsaws.

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If you haven’t seen them yet, take a look at @jbmanning5’s posts. His Glowforge launched him into a puzzle-making career, and he’s shared a lot of good tidbits with us here over the years.

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Indeed I’ve benefited from those posts (thanks, @jbmanning5!), though they don’t particularly lead in this direction — presumably because he’s focused on efficient production for a lower price point, and, I gather, because looseness of fit doesn’t bother him or most people.

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I remember him working on minimizing the looseness. He was playing with focus height, cutting face down, etc. I can’t remember now what technique he settled on, though.

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When I first got started with Glowforge, I used one of his kits w/ tutorial, and was pleased with the result. But I’m never satisfied; I always have to keep tweaking things! :wink:

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Now this is my kind of thing. Looking forward to your tutorial.

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Looking forward to your tutorial. Love the thought of cutting individually.

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I’m such a cheapskate that I probably wouldn’t do a puzzle this way due to material wastage. I do like a tight-fitting puzzle though! Your finished puzzles would be the Rolls-Royce of puzzles, and probably worth it for a very special puzzle.

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Are you cleaning the cut edges someway?
Really nice fits. Beautiful!

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You are so right about the fit. This is a great post.

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Yes, @cynd11, I completely agree; I’m only making these for family gifts. Though, some types of puzzles really need this approach; I’ll share a couple later.

The materials cost could be reduced (but it still wouldn’t be cheap) by

  • Using 11x17 instead of letter-size paper, to reduce waste on the margins. But larger jobs risk additional drift in Glowforge’s alignment during the cut (or even a spontaneous recalibration—I"ve seen it—that causes a noticeable jump). Also not many people have that size photo printer

  • Using traditional checkerboard piece shapes, instead of irregular piece shapes, for more efficient packing.

For the labor cost,

  • Half of it comes from masking/demasking. You can eliminate that if you cut right-side up and don’t care about small amounts of char. Or if you use lab-printed photos (which are very easy to demask) and don’t care about an inferior appearance at the edges.

  • Doing the alignment takes a couple of minutes per page. I hope (after I finish the tutorial) somebody will come and say “that’s lame, here’s a much easier method”. I’m sure there’s an easier way to do alignment if you’re cutting right-side-up.

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@brok09, you can use @jbmanning5’s trick of tumbling the pieces in kosher salt.

The plywood I use cuts pretty clean (especially if you’re used to chipboard). I cut it at speed 170, power 59 (YMMV).

There’s still quite a bit of char along the edge of the photo paper, though, which is capable of leaving a black streak if you rub the edge of the piece against something. You can mostly clean that by wiping the outside edges with a cotton rag, if you don’t want the salt tumbling.

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Using what I have on hand, I printed a test photo on Kirkland Glossy Inkjet paper using my Canon three-color plus black printer. HEATnBOND Ultra Hold thermal setting adhesive was used to bond the photo to 0.1 inch thick chipboard. There was no noticeable degradation in inkjet color on the photo due to heating.
I had no sealer, so applied medium tack masking directly to the cold glossy photo. No squeegeeing was necessary. Surfaces seemed to attract each other.
After cutting the tiles, it was impossible to remove the masking. Insistent picking left the masking “glue” still adhering to the photo paper .

Also made cuts without any masking on the photo which worked with little residue. But why this failure with masking on photo-paper?

Any recommendations for what masking to use and what sealer to use?

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You should open your own discussion for your issue, not hijack someone’s showcase thread. Custom materials and settings can not be discussed in this forum section.

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My apologies. Old age my only excuse for asking for help.

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I don’t use a sealer, because even the recommended ones tend to dull the image.

1. Solution

2. The other option is to use a printing service (photo lab). For whatever reason, their photos don’t have this problem, and de-mask easily. The resulting appearance is inferior; the edges are more prominent. But it might be good enough for your particular application. And it has the advantage of better durability.

3. If you really insist on using “photo paper”:

  1. Start with matte inkjet photo paper, which tends to be a little less sticky than glossy.
  2. Place the transfer paper sticky-side-up to the desk (taped down at the edges)
  3. Around 10 times: stick a piece of cardstock to it (with gradually increasing pressure with the squeegee), then pull it off.
  4. Around 10 times or more: stick a piece of spare photo paper to it (starting with very light squeegee pressure, increasing to medium), then pull it off.
  5. Stop when it feels only slightly tacky. There’s a very fine line between “too strong to pull off” and “too weak to do its job”. It takes practice.
  6. Apply the transfer paper to the photo, carefully avoiding introduction of bubbles, then lightly roll it down with a rubber roller (or you can manage with fingers). Again, the use of the right amount of force takes some practice.

Even after all of that, I usually get at least a few pieces that have to be recut, either because the masking was too strong and I couldn’t get it off, or it was too weak and the piece got discolored, or often both on the same page.

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There’s nothing wrong with asking the help. That’s why there are sections in the forum specifically devoted to it. Beyond the manual is the place to ask for help with dealing with non-proof grade materials and/or settings. Community support is the place to ask for help with machine issues.

Made on a Glowforge is the section for highlighting your work, and discussion of non-proofgrade materials and settings is not permitted.

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Oh thank you for your reply. And even after a previous chastisement for me. I wondered if Low Tack transfer paper would help but am reluctant to buy a whole roll to do the experiment. You are making the “low tack”. Nice solution.

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That’s the procedure I use with the “low tack” paper!

I just tried it with the “medium tack” paper. It took about twice as long to weaken, and the outcome wasn’t great. I’ll stick with the low-tack.

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Go here for the tutorial :slight_smile:

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