The thesis is based on 5 papers published between 2005 an 2015. You can access the complete thesis at this link. Starting by investigating the most common types of conservation treatment used on objects in the LSH collection, and elsewhere, to then empirically measuring the effect of those treatments on aged silk, Johanna sought to answer the question what effect is the conservation treatment I am carry out having on the costume that is being conserved? Evaluating the strength of aged silk after conservation required a way to age silk in such a way that it acquired properties equivalent to those of silk costumes from the 1600s, and methods to measure those properties. Further the aesthetic appearance of the conservation was assessed, the time to carry out the different types of treatment and the reason for carrying out conservation treatments.
Johanna's opponent was Joy Boutrop who started by praising the co-operation with scientists on other disciplines. It is not always easy to communicate and convince others that what you think is interesting and exciting will be interesting for them, but the co-operation is necessary to get access to specialist testing equipment and specialised knowledge. Joy also praised Livrustkammaren, Johanna's employer, for the support they have given her during the research. She also felt it was important that Johanna has managed to publish her articles, in this way the knowledge is shared not just sitting on the shelves in the university. A limitation in the research was pointed out - the artificially aged textiles are compared to aged silk from 1617 and 1654 - we don't know if the ageing cycles evaluated would give silks comparable to other periods. Joy was impressed that Johanna had investigated the strength of samples after removing the conservation treatment in order to measure how the treatment has weakened the sample. She was not aware of anybody else who has measured this.
In discussions between the opponent and respondent Joy questioned Johanna's choice of method to achieve accelerated wear. Washing seemed too harsh, and adds superfluous humidity. Joy suggested the accelerator test method, which combines stretching, bending and rubbing (see this article for more information about abrasion testing of textiles). Johanna was able to answer that she had tried this method but it had no effect on the samples.
Joy also asked why Johanna had not compared damaged but not conserved fabric with conserved after wear. Further the use of tensile test results compared to amino acid markers (see Johanna's paper III) as a method to evaluate the level of degradation of the silk fabric linked to available sample size was discussed. What can you cut from the object to carry out an evaluation? Where to take the sample? Is fabric from the seam allowance representative? If you take a thread from the damaged area is it too damaged? And should you take a sample at all? How much information will it give? What implication is there for the authenticity of the object? Being able to communicate a level of damage, between disciplines is enabled but is it justified?
How much does the handling involved in carrying out conservation treatment affect the costume? Is it better to open the seams or to insert a supporting fabric through the damage? Does opening the seams remove evidence?
Which is better remedial or passive conservation? Does passive conservation give the viewer the feeling that nobody cares about this object?
Katia congratulated Johanna on writing a thesis about practical hands on conservation. Her feeling is that less manipulation is preferable, and that is conservation results in damage then the objects should stay in storage and not be put on display. She stated that conservators need to learn to be story tellers, and to explain to visitors why there has been no intervention.
She felt that Johanna had missed a couple of important references including this one Ward, Philip R. 1986. The Nature of Conservation: A Race against Time. Marina del Rey, CA: Getty Conservation Institute. http://hdl.handle.net/10020/gci_pubs/nature_of_conservation_english.
Johanna had stated that she would now use more crepeline than support fabrics and couching. Katia agreed that crepeline would be a good signal to people handling the costume that the fabric is weakened, but argued that there was a risk that you cannot see where you are stitching and therefore might damage metal threads in the fabric weave. Johanna did not agree stating that you would feel the metal thread with your needle. Katia also wondered about the use of micro fading as a marker for degradation - Johanna agreed this was a possibility but that it was expensive, also that other researchers were already writing about this.
Katia was pleased that the thesis evaluated the manual skill of stitching. But wondered how we can elevate the courage of textil conservators to evaluate themselves and not "sew things to death". Johanna agreed and stated that she will use her findings in teaching to support students understanding of appropriate levels of intervention.
After coffee and Gustav Adolf bakelse the examination committee duly declared Johanna had passed and can now title herself Doctor.
Her work is important for the advocacy of textile conservation and has served to spark many discussions about the nature of textile conservation for objects in use compared to those in museum collections. As the first member of SFT to complete studies at this level she is an inspiration and example to us all, future students will benefit greatly from her findings.
SFT extends their warmest congratulations.