Microfading Tester International Discussion Group

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  • 1.  Seeking advice and experiences with MFT on a 24 m long textile artwork

    Posted 09-11-2026 05:22

    Hi everyone,


    I am part of the team working on a project involving a large contemporary textile artwork (24 m in length and 39 cm in height), and we would be very grateful for any advice or experiences the MFT community may be willing to share.


    The artwork consists of two separate sections that join together: a smaller section of approximately 7.5 metres and a larger section of approximately 15.5 metres, giving a total length of around 24 metres. Both sections are continuous pieces of fabric without seams.The ground fabric is a bleached plain weave linen; this fabric is not fully opaque. The design is created with embroidery in wool, printed elements and appliqued fabrics. The printing consists of two colours, blue and gold.  The embroidery is to some extent three dimensional and full of tiny details. For the appliqué are used two different fabrics, sewn onto the linen: a very pale blue silk crepeline, which is an extremely thin and semi-transparent fabric, and a printed satin. It has a loose cotton lining which was added for the display. 


    As we prepare for microfade testing, we would be very interested to hear about any experiences, recommendations, or lessons learned from working with large-scale textiles. Any insight would be valuable, including:
    •    Approaches to selecting measurement points across a large and diverse artwork (techinque and material wise)
    •    Balancing representativeness with the practical limitations on the number of measurements
    •    Experiences with testing printed textiles, wool embroidery, silk crepeline, appliqué elements, or modern textile materials
    •    Handling considerations before and during testing
    •    Documentation strategies and decision-making frameworks
    •    Any particular dos and don'ts that you have found useful in similar projects


    The purpose of the testing is to support decisions regarding future exhibition lighting design, illumination levels, and long-term display conditions.


    We would greatly appreciate hearing about both successful approaches and challenges encountered in similar projects, especially in connection to doing MFT on textiles. 
    Many thanks in advance for your thoughts and experiences.

    Natalija 



    ------------------------------
    Natalija Ćosić, PhD
    Senior Preventive Conservator and Cultural Heritage Researcher
    Shared Conservation Department, MuHo, Bergen, Norway
    ICOM CC Preventive Conservation Working group - AoC
    ------------------------------


  • 2.  RE: Seeking advice and experiences with MFT on a 24 m long textile artwork

    Posted 09-12-2026 05:51

    Hello Natalija,

    I have significant expertise in MFT instrumentation and application ton a wide range of materials including large, but not that large, textiles of similar description. Moreover, I am based in Sweden and am the Fotonowy distributor for the Nordics. I have several MFT for different needs, and I am happy to discuss your application with you.

    Best regards 

    Jacob Thomas 



    ------------------------------
    Jacob Thomas

    jacoblthomas@gmail.com
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  • 3.  RE: Seeking advice and experiences with MFT on a 24 m long textile artwork

    Posted 09-14-2026 01:45
      |   view attached
    Dear Natalija

    We use a modified Thomas retroreflective 0:15° MFT unit with an LED source and a 50mm forelens that produces a ~0.6 mm diameter spot at about 1.5 Mlx intensity. 

    There are several approaches to large textiles. One approach is to use a long horizontal beam, supported either side of the textile, to support the MFT head. Another is to roll or fold the textile to bring the color in question close to the MFT head on a more conventional rigid mount such as a photographic studio stand.

    When we are doing textiles, we will quite often put the MFT on a 3D printed 15° stand, place a sheet of 1/8" borosilicate glass on the area of the textile to be measured, and then place the MFT+stand on the glass. Of course, this can only be done if the textile is sufficiently robust, but quite often the robustness of the textile is not a problem. The weight of the MFT+stand pressing on the glass provides a little weight to help flatten and compress the "fluffy" areas of the textile which otherwise interfere with getting a good reading from the bulk material.  See the attached image for an example.

    For this method to measure color change correctly, you have to take the spectrometer dark ref and white ref through the same glass. You should also be cautious about moving the head around too much, since changing the bend in the fiber optic cables too much can alter the white reference. You also have to be careful when focusing to focus on the textile rather than focusing on the top surface of the glass.

    If your textile is thin, you may want to investigate whether you are getting any contribution reflected from the surface underneath the textile. You can do this by taking some readings with and without a solid-colored card underneath the textile to see if the color of the card affects the color of the spectra that you collect.  If you are getting contribution from below the fiber, you may want to think about isolating the textile from the table a little (e.g., using glass or plexiglas below the textile).

    One of the more annoying potential issues with dyed textiles fading under intense illumination is the possibility of reversion.  In general, we do not check for reversion unless the color is very fugitive.      

    On the question of the number of points to measure: we typically will survey all colors, but not necessarily all shades of all colors. We will start out using a quick protocol (if >= BW3 after two minutes, repeat on a nearby area to confirm, and then move on to the next color; if < BW3 go for eight minutes) which gets us a reasonably rapid list of the sensitive colors. Depending on what we find in the quick stage, and how extensive a particular color is, we may go back and do more extended replicate readings for the more sensitive colors.

    JP

    JP Brown (he/his)
    Senior Conservator
    Vice-Chair MFT-IDG

    Field Museum
    1400 S. DuSable Lake Shore Dr.
    Chicago, IL 60605





  • 4.  RE: Seeking advice and experiences with MFT on a 24 m long textile artwork

    Posted 09-14-2026 14:44
    Hi,  Natalija,

    Given the size of this object, I am wondering what is the planned display environment and potential light sources: outdoor display, indoor display with natural light through windows (and UV shielding), or completely in a room with no natural light, relying on warm-white LEDs?  This will determine the light source for MFT: Xe with UV+IR filters or LED.  Cool-white LED (~4000K CCT) may visually appear like daylight through windows, but it missing a small portion of near-UV and voilet components (invisible but more damaging than the 450-470nm blue-pump in cool-white LED).  Xe with UV+IR filters would be closer to simulate the ligh profile of natural light through UV shiled windows.

    Some printed fabric materials (especially those designed for outdoor display) may have high lightfastness.  To induce a measurable delta-E significantly beyond the noise level may require an exposure duration much longer than the typical test duration most of us use (within a timeframe of minutes to hours).  I have compared light-fading tests on photographic prints of pigment inks using Xe-MFT vs. other test labs using conventional light-fading test chambers.  I could only achieve a fraction of what they achieved in terms of total light dosages (40-60 Mlx.-hr.), and they captured color fadings after weeks of exposure, way beyound what I could detect under Xe-MFT within a day.

    Risk of reciprocity failure, when attempting to project the light fading rate under real display conditions from a highly accelerated light fading test.  That is typically assume a single stress factor in the play (light only), and ignore the impact of other factors over a very long exposure duration, for example, O2, which are insignificant in short exposure of minutes and hours, but become significant in years and decades on those colorants that show synergistic effects with light+O2 on the chemical degradation.  

    Finally, narrowing the test error range with limited tests on fabric media is also challenging, when the size of the light spot is close to the woven surface features of a fabric media.  We all see this with ISO Bluewool: the fading rate varies depending on the angle of the exposure light vs. the yarn surface.  I usually move the light spot slowly over the fabric surface of a same color zone until the detected light signal reaches its maximum, and then test that spot. 

    Hope the above is helpful to your endeavor. 

    Henry Duan, Ph.D.
    Preservation research scientist
    NARA of US







  • 5.  RE: Seeking advice and experiences with MFT on a 24 m long textile artwork

    Posted 10 hours ago
    Hi everyone,
     
    First and foremost, my apologies for this very late reply, and a big thank you to everyone who responded so quickly and generously to our post.
     
    As it happened, I posted this just before ICOM-CC in Oslo, which gave me the opportunity to meet some of you in person and to discuss many of your suggestions with the rest of our team. Thank you very much for sharing your experience and practical advice. I would also like to thank everyone who followed the discussion and contributed through comments and follow-up questions. It gave us a lot of useful input and plenty to think about as we planned the testing.
     
    A small update from our side: at the beginning of October, we carried out what we feel was a very successful MFT campaign, and we are very pleased with how it went. We are now organising and analysing the data and continuing to work with the results as part of the wider project.
     
    We hope that, at some point, we will also be able to publish both the process and the results. 
     
    Thank you again for your generous support and for sharing your knowledge with us.
     
    Warm regards on behalf of the whole team,
     Natalija


    ------------------------------
    Natalija Ćosić, PhD
    Senior Preventive Conservator and Cultural Heritage Researcher
    Shared Conservation Department, MuHo, Bergen, Norway
    ICOM CC Preventive Conservation Working group - AoC
    ------------------------------



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