I just got my Bambu Lab X1C with AMS on Monday (super excited!). After successfully printing a few items like a custom PLA-CF lock and some tools in standard PLA, I ran into an issue while printing Gridfinity boxes using a spool of “Bambu PLA Silk Purple.”
The prints look absolutely stunning but have zero strength. The layers don’t seem to stick at all, and the prints are extremely brittle—falling apart with the slightest handling. In contrast, the same models printed with “Bambu PLA Matte Grey” filament come out strong and nearly unbreakable, so I’m confident the slicing and modeling are fine.
Here’s what I’ve done so far:
First print: Used the default settings for Silk PLA in Bambu Studio.
Second print: Increased the nozzle temperature by 5°C.
Third print: Dried the filament for 5 hours in my Sunlu Filament Dryer S4.
Fourth print: Used the dried filament with the nozzle temperature increased by 10°C.
All prints were done with the “0.20mm strength @BBL X1C” profile on the X1C, using the 0.4 nozzle, and loading the filament through the AMS.
Each print looked beautiful when removed from the printer, but they were still incredibly brittle. The layers separate with little effort, while the Bambu PLA Matte Grey version holds up to significant bending without breaking.
Has anyone encountered similar issues with Bambu Silk PLA or AMS-loaded filament? Could it be a filament quality issue, or should I try tweaking other settings? Any advice would be much appreciated!
This has been my experience with two rolls of silk filament. “They” say you should print it slower, however nothing I tried ever made it better. Vase mode prints unraveled like a loose thread on button. Printing big solid blocks helped the adhesion, so maybe it’s good for ornaments. Even printing it on my old dead slow Ender 3 I had the same results. I put the remaining in the bin and moved on. The Bambu Metal PLA seems to be much better but the colours are limited.
Wow, I just read Duane777’s response, and I’m honestly shocked. I also found this section in the Bambu Lab wiki about Silk PLA: Printing with Silk Filaments. It’s clear Silk PLA has significant limitations when it comes to strength and layer adhesion, even with adjustments like slowing down the print speed or increasing temperatures.
The part that really surprises me is why Silk PLA is being sold at all if it’s so unreliable for functional prints? I just bought seven more spools of Silk PLA (3 in other colors and 4 dual-color spools because I thought they sounded cool). Now, I’m worried I’ve wasted money on filament that might not work for anything other than ornamental or low-stress prints.
I’ll definitely try the recommended settings from the Bambu Lab wiki soon, but my hopes aren’t high after reading Duane777’s experience. If Silk PLA is only good for aesthetics and not for practical prints, why isn’t that made clear in the product descriptions?
Does anyone have suggestions on what to do with Silk PLA? Can it be useful for anything practical, or should I just stick to purely decorative prints? And has anyone had success returning spools or getting refunds if they turn out to be unusable for your needs?
I feel like I’m in a bit of a bind here, so any advice would be super helpful. Thanks in advance!
I’ve never used silk pla, but I would treat it like any other new-to-me filament: Calibrate it in OrcaSlicer using the models in the top line calibration menu.
A temperature tower will isolate the best temp to use for appearance, bridging, and strength. Then optimize flow ratio and pressure advance.
I’ve been working on a project using Bambu PLA and Bambu silk PLA and am not seeing issues with the silks. They look beautiful printed using the standard Bambu profiles.
I’m a broken record on what might be the main factor - my filament actually is “dry”. I use a dry air flow into my filament dryer and monitor humidity in the filament dryer. I pull the spool when dryer humidity gets to 19% RH and store the spools in poly cereal storage boxes.
Not enough information to say the issue is water but it may be?
Printed yesterday - silk silver trim on silk copper body.
I just tried another print with the settings specified in the wiki, and it still comes out super brittle.
I’ll give it another run in the dryer, and another test run. If that does not work, I’ll return my incoming Bambu silk spools and buy some regular PLA.
I forgot to add, I was using generic silk PLA. I haven’t tried Bambu’s silk but based on your results my experience was the same. One would assume the default profiles would produce usable parts, after all this is the reason we buy Bambu or Prusa filaments which you would think should give you the best results. I have a similar experience with Bambu PETG Basic, the standard profile produces very brittle parts. I printed a dirt bin 10 hours 400g and it slipped off the table and broke, very dissapointing and a complete waste of time and energy.
I wanted to share an update after trying everything I could to make Silk PLA work.
Last night, I dried the filament overnight and added fresh silicone desiccant to the AMS. The air humidity was below 18% RH, and the AMS reported a humidity of 1. I printed a large litter bin with thin walls (link to the model here) using the recommended settings from the Bambu Lab Silk PLA wiki.
While the print looks stunning, the strength is still lacking. Applying even light pressure causes it to break along the layer lines (see attached photos). It’s slightly stronger than the Gridfinity boxes I printed earlier, likely because of the structure, but it’s still far too brittle to be functional.
At this point, I’m giving up on this roll of Silk PLA. I’ll be returning the incoming spools of Silk PLA and switching to more reliable filaments. I may try one of the multicolored silk spools for laughs and giggles, but I have very low expectations now.
Photos of the latest print and the break for reference:
That does look really good! So good I’d say your printer is printing properly. Is there infill in the walls of that?
The reason I ask is infill can add a lot of strength to the walls that might prevent that? Maybe another wall loop? Less hopeful of added wall loops helping over infill.
For testing, I’ve primarily been printing the Gridfinity box as my test object. It prints perfectly in PLA Basic and PLA Matte, with no issues at all. The problems seem isolated to PLA Silk, where the models are brittle and suffer from poor layer adhesion.
I’ve also used PLA-CF and PETG, and both materials print beautifully without any issues. In fact, my printer has been running non-stop since I got it six days ago, and it’s been performing flawlessly—even handling an automatic spool swap in the AMS today. I’m absolutely loving the X1C so far.
The only disappointment has been this spool of PLA Silk. Unfortunately, it just hasn’t lived up to expectations.
I wanted to share an update on my ongoing issues with Silk PLA.
The models I’ve tested all feature massive walls without infill, with the latest being an insert for the board game Blood Rage, where the walls are 1.6 mm thick.
Against my better judgment, I decided to test a spool of Bambu PLA Silk Copper to see if the results differed from the Purple Silk. Unfortunately, the outcome was the same. I tested both the default settings and the slower settings recommended in the Bambu Lab Silk PLA wiki. Both prints came out brittle, with poor layer adhesion, and the slower settings doubled the print time without improving the quality.
For reference, I’ve printed several identical models using regular PLA and Matte PLA under the same conditions, and they all came out strong and flawless.
Conditions for Testing Silk PLA:
Filament Drying: Bambu Silk PLA dried to RH < 20%
RH in AMS: 10%
Speeds:
Outer wall: 40 mm/s
Inner wall: 100 mm/s
Accelerations:
Normal printing: 5000 mm/s²
Outer wall: 3000 mm/s²
Given these consistent failures, I’ve decided to stop using Bambu Silk PLA altogether. Once I’ve received the remaining spools I ordered, I’ll be contacting Bambu Lab support to inquire about their refund procedure.
Below is a photo of the resulting Blood Rage insert printed in Silk Copper PLA. The model broke with light pressure in my hand:
Bambu is discontinuing the current line of silk PLA for a new formulation. I’ve been working on some big silk PLA pieces and am not having any issues though. The pieces seem quite strong and have taken multiple assembly/disassembly procedures with no separation or any issues.
I do use infill and am confident my filament is very dry because of the way I dry it. But these show the size and silk colors - Bambu silk PLA copper and silver for the major components and no issues. It definitely extrudes differently. The poops are larger diameter and very shiny. But it prints well here. The walls are about 1/4” thick and the silver housing is a large print using most of the X1C print volume.
I ran yet another test, this time with Bambu’s Blue/Green Silk PLA.
The results were slightly better—this print was noticeably less brittle than the Copper or Purple ones. However, it still breaks under light pressure applied with one hand, which makes it unsuitable for thin-walled models.
At this point, I’m officially giving up on printing anything with thin walls using Silk PLA.
I haven’t used Bambu’s Silk PLA … primarily used Sunlu Silks but most of my prints are a little thicker and more related to Cosplay type items for friends. Currently printing a Destiny 2 Hawkmoon and an Ace of Spades. I tried doing them in PETG (but the spools that arrived were a little wet so decided Silk since both will primarily hang on the wall according to the two that requested them (yes I explained the difference between PLA, PLA Silk, and PETg).
I love the look of silk PLA, but I don’t use it for anything thin, anything that has any pulling or pushing forces applied to it or structural stuff. It works great for small thicker decorative things though like this. The top is Bambu silk copper.
so decided Silk since both will primarily hang on the wall according to the two that requested them (yes I explained the difference between PLA, PLA Silk, and PETg).