Is It Worth Buying a Second-Hand Shell Jacket? An Evaluation of Shell Jackets’ Functionality and Price over Time

Round 1

Reviewer 1 Report

The researchers did not test from the front of the product, which I think is a big mistake, because it is the front of the product that experiences high wear factors.

Some tests were performed with inadequate equipment (as the researchers also admit), so it is unethical to draw some conclusions.

Many of the results are analyzed based on assumptions, so the conclusions of the study can be called into question.

Author Response

The researchers did not test from the front of the product, which I think is a big mistake, because it is the front of the product that experiences high wear factors.

→ Where shell jackets experience high wear factors can be discussed and from our understanding it highly depends on the specific use of the jackets. Is the jacket used during winter or summer? In wet or dry conditions? With or without a backpack? Etc. In this study the samples were simply cut in places where a 200x200 mm test sample was possible to fit on all jackets. Due to a lot of seams and trims on the front of the jackets, in addition to the presence of pockets, samples were unfortunately not possible to be cut there. If possible, it would have been great to add samples from both the jacket’s front and lower arms.

Some tests were performed with inadequate equipment (as the researchers also admit), so it is unethical to draw some conclusions.

→ If inadequate equipment refers to the Akustron air permeability tester only being able to measure air permeability greater than 3 mm/s our opinion is that the accuracy of the tester was good enough. Of course, it would have been interesting from a material point of view to know whether the air permeability changed at all over time, but from a user perspective it does not matter since it is generally accepted that air permeability below 5 mm/s is perceived to be fully windproof and all of the jackets fulfil this criteria. Clarified on lines 293-295.

If inadequate equipment refers to the fact that three of four material tests were performed in an unconditioned lab, the comment is justified. All textile fibres absorb moisture from the surrounding environment which affect the properties of the textiles, e.g. strength. However, all jackets of the study are made of synthetic fibres which have a rather low absorbency. In addition, the tests performed in the uncontrolled environment (air permeability, water repellency, and breathability tests) are not related to the strength of the fibres. To test the tensile strength, tear strength, pilling or abrasion resistance would have been more critical. However, it is reasonable that the breathability test is to some extent affected by the low RH of the unconditioned lab. In the end, our opinion is that the overall pattern of the results is not affected using an unconditioned lab.

Many of the results are analyzed based on assumptions, so the conclusions of the study can be called into question.

→ Maximum value for air permeability and water repellency was not assumed, it is a fact that shell jackets are fully windproof and water repellent. See line 198.

Assumptions e.g. averages were used for missing data of age, original price, and original breathability to enable the use of all jackets for the analysis of functionality over time. To use all jackets was crucial due to the small sample size of the study. For example, if average was not used for original breathability only 5 jackets would have been possible to include in the analysis of breathability over time.

In the first section of the discussion, it is stated that the results are indicative due to the small sample size. Now it is also added that the results are indicative due to some missing data of age, original price, and original performance. See lines 262-263.

The fact that the study has some limitations is added to the conclusion, see lines 434-436.

Reviewer 2 Report

This article presents an interesting study on a set of physical and mechanical textile parameters of second-hand jackets - air permeability, water repellency, water penetration and breathability - and analyzes how the selected parameters and price vary over time. The discussion highlights the importance of testing and communicating the quality of second-hand products to improve consumer confidence and products life cycle.

It is a relevant research topic and it falls within the scope of the Sustainability Journal. Nevertheless, in my opinion, the paper presents several issues that should be addressed previously to manuscript publication.

Lines 119-121: “In the research field of textile aging, membrane laminates have until now only been aged and evaluated for their resistance to temperature and washing”. The authors should further review the literature, there are several examples considering other evaluations, namely, colorfastness to several conditions, abrasion resistant, shrinkage, etc. 

Section 2.5 Calculation and visualization of the results is too vague. The methods used to treat and analyze data need to be further described.

Lines 275-7: “The equipment used to measure air permeability within this study was only able to measure air permeability greater than 3 mm/s.” This information should be presented in the 2.1 Test Methods section.

In section 4, The concept of ‘timeless design’ is not articulated clearly, particularly in lines 406-08 “Timeless design needs to be adopted by manufacturers at an early stage, already in the design phase of the jackets.”. In lines 408-9 “Applying timeless design removes the influence of appearance related to brand, design, colour etc.” This phrase raises several fundamental questions. The concept of ‘timeless design’ needs to be reviewed and introduced using references. 

The selection of the 4 properties to evaluate the jackets quality can also be discussed, namely, the importance of the water repellency test result to inform consumers of the product quality being subjective as this property is tailored with the re-applied DWR.

Furthermore, in section 4, the authors discuss technical limitations in implementing the physical tests conducted on a larger scale for second-hand products. Although, they still present it as a finding of the work in the Abstract as well as in the Conclusions. 

In the Abstract, lines 21-23: “The results demonstrate the potential of using physical testing when setting resale prices, as an aid to the consumer to understand the level of performance they can expect from a used product”. In what way the potential was demonstrated? Further consumer tests and resale price studies would be required to demonstrate it. Besides, there are limitations of tests' implementation and requirements to overcome them, which can be mentioned.

In the Conclusions, lines 424 “The results demonstrate the benefit of timeless design”. Again, how it was demonstrated? 

The conclusions are too brief and further clarification of the findings is needed. I consider that at this moment, the conclusions are not thoroughly supported by the research and results presented.

Author Response

This article presents an interesting study on a set of physical and mechanical textile parameters of second-hand jackets - air permeability, water repellency, water penetration and breathability - and analyzes how the selected parameters and price vary over time. The discussion highlights the importance of testing and communicating the quality of second-hand products to improve consumer confidence and products life cycle.

It is a relevant research topic and it falls within the scope of the Sustainability Journal. Nevertheless, in my opinion, the paper presents several issues that should be addressed previously to manuscript publication.

Lines 119-121: “In the research field of textile aging, membrane laminates have until now only been aged and evaluated for their resistance to temperature and washing”. The authors should further review the literature, there are several examples considering other evaluations, namely, colorfastness to several conditions, abrasion resistant, shrinkage, etc. 

→ To our knowledge no literature on other evaluations exist that are related to membrane laminates of shell jackets or other outdoor wear. We are aware of literature concerning the evaluation of protective clothing membrane laminates but due to the difference in use between outdoor wear and protective clothing this literature is not brought up in this study. That this statement only concerns shell jacket membrane laminate for the consumer segment is now clarified, see lines 120-121.

Section 2.5 Calculation and visualization of the results is too vague. The methods used to treat and analyze data need to be further described.

→ Section 2.5. Calculation and visualization of the result updated, see lines 214-229.

Lines 275-7: “The equipment used to measure air permeability within this study was only able to measure air permeability greater than 3 mm/s.” This information should be presented in the 2.1 Test Methods section.

→ Section 2.1 Test Methods updated, see lines 160-161.

In section 4, The concept of ‘timeless design’ is not articulated clearly, particularly in lines 406-08 “Timeless design needs to be adopted by manufacturers at an early stage, already in the design phase of the jackets.”. In lines 408-9 “Applying timeless design removes the influence of appearance related to brand, design, colour etc.” This phrase raises several fundamental questions. The concept of ‘timeless design’ needs to be reviewed and introduced using references. 

→ Section 4 Discussion updated, see lines 419-425.

The selection of the 4 properties to evaluate the jackets quality can also be discussed, namely, the importance of the water repellency test result to inform consumers of the product quality being subjective as this property is tailored with the re-applied DWR.

→ The four functionalities were chosen since these are the four main functionalities of shell jackets that contribute to the jackets’ overall performance. Test that we have performed showed that second-hand jackets do not get fully water repellent after reapplication of DWR. In average the water repellency of the second-hand jackets only increases by 20% after DWR reapplication. Water repellency is therefore still interesting to evaluate. This is to some extent highlighted in lines 297-306.

Furthermore, in section 4, the authors discuss technical limitations in implementing the physical tests conducted on a larger scale for second-hand products. Although, they still present it as a finding of the work in the Abstract as well as in the Conclusions. 

In the Abstract, lines 21-23: “The results demonstrate the potential of using physical testing when setting resale prices, as an aid to the consumer to understand the level of performance they can expect from a used product”. In what way the potential was demonstrated? Further consumer tests and resale price studies would be required to demonstrate it. Besides, there are limitations of tests' implementation and requirements to overcome them, which can be mentioned.

In the Conclusions, lines 424 “The results demonstrate the benefit of timeless design”. Again, how it was demonstrated? 

The conclusions are too brief and further clarification of the findings is needed. I consider that at this moment, the conclusions are not thoroughly supported by the research and results presented.

→ Abstract updated, see lines 11-24.

→ Conclusion updated, see lines 432-446.

Reviewer 3 Report

It is an interesting study, however I suggest that the following aspects be reviewed: - it is necessary to extensively detail the collection of samples, although it is true that some information is explained, it would be interesting to know the brands of the jackets, photographs that show possible visual elements that affect the quality/price assessment, among others.

- It could be analyzed if the prices were statistically correlated with the age of the garments, although that data is also not clear, that is, how did they determine the age of the jacket?

- Another aspect that remains unanalyzed, is the type of material of the jacket that although it is analyzed, the characteristics of each type of fabric are not explained which can be a forecast of its durability over time.

Author Response

It is an interesting study, however I suggest that the following aspects be reviewed:

- it is necessary to extensively detail the collection of samples, although it is true that some information is explained, it would be interesting to know the brands of the jackets, photographs that show possible visual elements that affect the quality/price assessment, among others.

→ We have chosen to not mention the brand of the jackets since we believe that the technology and material of the jackets are more relevant than the actual brand of the jackets. As the full history of the jackets we tested is unknown, we also feel it would be potentially unfair to a brands reputation to highlight any potential weaknesses that are specific to an individual jacket, and not necessarily a reflection of the brands’ quality.

In this study we have only focused on objective evaluation of the jackets’ membrane laminates. In a coming study, that will build upon this study, a larger sample size of second-hand and end-of-life shell jackets will be subjectively evaluated e.g. ocularly inspected before the membrane laminates of the jackets are evaluated.

- It could be analyzed if the prices were statistically correlated with the age of the garments, although that data is also not clear, that is, how did they determine the age of the jacket?

→ Section 2.3. Jacket specification and original performance updated, see lines 186-190.

- Another aspect that remains unanalyzed, is the type of material of the jacket that although it is analyzed, the characteristics of each type of fabric are not explained which can be a forecast of its durability over time.

→ This is an important observation, and will be dealt with in the already mentioned coming study of second-hand and end-of-life shell jackets which will look at a much larger sample set. We feel unable to generalise to a specific membrane or textile technology based on the few samples in this paper, but believe that the general trends in durability seen here are representative.

Reviewer 4 Report

The manuscript entitled “Evaluating functionality and price of second-hand shell jackets over time” deals with an interesting and important topic that fits perfectly in the journal’s scope. I have, however, some – mainly – minor concerns that need to be addressed.

Please, clarify the base year for 63% increase in line 37. The meaning of asterisks in Table 1 and 2 is missing. Why did you choose the four functionality measures to examine? Why not others? Please, include the explanation in the Materials and Methods section. You combine the four functionalities but you provide information about the specific combination method only in the Discussion section. Please, include this information in section 2.5. Moreover, isn’t there any information about the relative importance of these four characteristics for the consumers? Those importance values would serve as excellent weights for weighting averages; simple average can be very misleading (especially with the small sample size). Another problem is the handling of missing information: why did you use averages for the age, original price, and original breathability, while for water resistance, air permeability, and water repellency, you applied the maximum value? I recommend you to skip the missing values from analysis; substitution might distort the results significantly. Please, provide more information on how you fitted the lines on the data points (linear regression? computing CAGR?); what are the linear equations? What are the correlations between price and functionality (separately and combined)? What is the source of your statements about the origin of the decrease in water repellency, water penetration resistance, and breathability in lines 284-287? How do users apply new DWR after every wash? I have never heard about that (which does not mean it does not exist but it needs more explanation). Please, make it clearer what the practical relevance of your research results is, since the four functional characteristics of each jacket cannot be examined in retail settings based on your method (because it would be too costly and it would damage jackets); therefore even if we have laboratory estimations on the relationship between age and functionality (even more precise estimations than those in this study), we can only provide an estimated price according to the estimated functionality, but it still cannot guarantee that the specific jacket is in the estimated condition, thus, the consumers would still feel high level of uncertainty before purchase.

Please, eliminate unnecessary spaces between numbers and percentages (and once Celsius degree). Besides, there are some grammar mistakes and typos, see, e.g., in lines 41 and 327.

Author Response

The manuscript entitled “Evaluating functionality and price of second-hand shell jackets over time” deals with an interesting and important topic that fits perfectly in the journal’s scope. I have, however, some – mainly – minor concerns that need to be addressed.

Please, clarify the base year for 63% increase in line 37. The meaning of asterisks in Table 1 and 2 is missing. Why did you choose the four functionality measures to examine? Why not others? Please, include the explanation in the Materials and Methods section.

→ The 63% increase clarified, see lines 35.

Asterisk meaning was previous mention in the table texts, to clarify the explanation was removed from the table text and put as a foot note.

The choice of the four functionalities is mentioned in Material and Methods section: “The functionalities of interest in this study were based on the requirements of shell jackets to be waterproof, wind resistant and breathable. Air permeability, water repellency, water penetration resistance, and breathability, are generally accepted to be the four main functionalities of shell jackets that contribute to the jackets’ overall performance.”

You combine the four functionalities but you provide information about the specific combination method only in the Discussion section. Please, include this information in section 2.5. Moreover, isn’t there any information about the relative importance of these four characteristics for the consumers? Those importance values would serve as excellent weights for weighting averages; simple average can be very misleading (especially with the small sample size).

→ Information about how the four functionalities were combined for total functionality is added in 2. Materials and Methods, see lines 219-220. It is desirable to weight the functionalities according to the consumers perception instead of simply weighing them equally. Unfortunately, information about consumer perception have not been found in relation to shell jackets and these specific functionalities. It would therefore require an additional study. As all parameters showed relatively gradual decreases over time, we believe that equal weighting is sufficient to show the general performance trend.

Another problem is the handling of missing information: why did you use averages for the age, original price, and original breathability, while for water resistance, air permeability, and water repellency, you applied the maximum value? I recommend you to skip the missing values from analysis; substitution might distort the results significantly.

→ Maximum value for air permeability and water repellency was not assumed, it is a fact that shell jackets are fully windproof and water repellent. Clarified on line 198.

Assumptions e.g. averages were used for missing data of age, original price, and original breathability to enable the use of all jackets for the analysis of functionality over time. To be able to use all jacket is crucial due to the small sample size of the study. For example, if average was not used for original breathability only 5 jackets are possible to include in the analysis of breathability over time.

Regadring skipping missing values, additional analyses were conducted but no significant distortion was observed. We agree this is relevant information for the reader so we have updated our discussion to include this consideration, see lines 264-270.

Please, provide more information on how you fitted the lines on the data points (linear regression? computing CAGR?); what are the linear equations? What are the correlations between price and functionality (separately and combined)? What is the source of your statements about the origin of the decrease in water repellency, water penetration resistance, and breathability in lines 284-287? How do users apply new DWR after every wash? I have never heard about that (which does not mean it does not exist but it needs more explanation).

→ Section 2.5 Calculation and visualization is updated to clarify the visualization of the results, see lines 217-229.

We have described the function of the DWR in 1. Introduction lines 109-114 and 2. Materials and Methods lines 151-152.

Clarification on DWR reapplications added in 1. Introduction, see lines 111-114.

Please, make it clearer what the practical relevance of your research results is, since the four functional characteristics of each jacket cannot be examined in retail settings based on your method (because it would be too costly and it would damage jackets); therefore even if we have laboratory estimations on the relationship between age and functionality (even more precise estimations than those in this study), we can only provide an estimated price according to the estimated functionality, but it still cannot guarantee that the specific jacket is in the estimated condition, thus, the consumers would still feel high level of uncertainty before purchase.

→ The aim of the study is to evaluate the functionality of real used products and to evaluate whether the price setting for resale correlates with the actual condition of the jackets. The aim is not to use the same material tests as used in the study for price setting in the second-hand stores, nor to base the price setting in the second-hand stores on the results of the study. However, the potential of using some sort of non-destructive material tests is discussed but we agree, that needs further studies and development of non-destructive test methods.

Please, eliminate unnecessary spaces between numbers and percentages (and once Celsius degree). Besides, there are some grammar mistakes and typos, see, e.g., in lines 41 and 327.

→ Corrected.

Round 2

Reviewer 1 Report

Accept in present form

Reviewer 2 Report

Overall, the work was improved and I consider it deserves publication in the Sustainability journal.