Select Page


Diné (Navajo) Blanket or rug, 1880-1890. Wool. IAF.T6. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.

Diné (Navajo) Blanket or rug, c. 1890. Wool. 53 x 43 in. (134.6 x 109.2 cm). IAF.T15. Photo by Addison Doty. Copyright 2022 School for Advanced Research.

Diné (Navajo) Blanket or rug, 1880-1890. 51 x 68 in. (129.5 x 172.7 cm). IAF.T56. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.

Image Caption: IAF.T6, IAF. T15, and IAF.T56: These textiles were chosen for this exhibition based on Venancio Aragon’s recommendation that the exhibition show a range of techniques and types that go beyond their history of chemical treatment. These three pieces were created using wedge weave technique.

What does it mean to care for belongings? Native American communities have long known that belongings are not inert; they have life and agency that is as important to care for as their physical material. In many cases, cultural belongings physically hold the knowledge and skill of past generations that people can learn from today. However, from the 1880s through the 1970s, museums frequently used pesticides to guard materials against pests like moths, beetles, and rodents. Pesticides preserved material physically but left behind toxic residues that remain today, making textiles harder to access.

The Indian Arts Research Center (IARC) collection includes over one thousand textiles made by artists from many different communities. This exhibition features some of the chemically treated Diné pieces within the collection. These textiles range in time period and utility. Guided by the perspectives of Diné weaver Venancio Aragon, along with insight from IARC collections manager Laura Elliff Cruz, the exhibition makes a small sample of what is present in the IARC textile collection virtually accessible, while discussing the legacies of colonial care in museum collections.

[The selected textiles featured in this exhibition showcase a variety of weaving techniques and styles. However, as a non-Native person and a non-weaver, I do not purport to understand the cultural complexities and underlying significance. To learn more about Diné weaving, I suggest Weaving a World: Textiles and the Navajo Way of Seeing, written by Roseann S. Willink (Diné) and Paul G. Zolbrod and also learning from contemporary weavers themselves.] [1]

Curated by Penske McCormack, 2022-2023 Anne Ray Intern.


The myth of the “vanishing Indian” inspired many non-Native individuals and institutions to collect Native art and belongings in North America. These institutions falsely believed that if they did not, both the materials and the skills required to produce the belongings would disappear. This meant protecting against destructive pests. Pesticides were cheap, effective deterrents to pests, and in many cases did not alter the appearance of the material. Museums understood little about how dangerous the chemicals could be. Multiple institutions in the area, including the Museum of New Mexico, the Laboratory of Anthropology, and the School of American Research (now School for Advanced Research), used the arsenic-based mothproofing treatment “Sibur” around the middle of the 20th century.[2]        

Diné (Navajo) saddle cover (Front view), 1920-1930. Churro wool, dye. 27 x 14 in. (68.6 x 35.6 cm), Cat no. IAF.T29, Photo by Addison Doty.
Diné (Navajo) saddle cover (Front view), 1930-1940. Churro wool, dye. 16 15/16 x 31 1/8 in. (43 x 79 cm). Cat no. SAR.1963-5, Photo by Addison Doty.
Diné (Navajo) saddle cover (Back view), 1920-1930. Churro wool, dye. 27 x 14 in. (68.6 x 35.6 cm), Cat no. IAF.T29, Photo by Addison Doty.
Diné (Navajo) saddle cover (Back view), 1930-1940. Churro wool, dye. 16 15/16 x 31 1/8 in. (43 x 79 cm). Cat no. SAR.1963-5, Photo by Addison Doty.

Image Caption: IAF.T29 and SAR.1963-5: These pieces exhibit the “tufting” technique, using individually dyed tufts of Navajo-Churro sheep wool. IAF.T29 was siburized in 1950 at the School Advanced Research. SAR.1963-5 was “mothproofed” in 1964. The chemical used is not specified, but may have been arsenic-based.


Museums no longer use pesticide treatments on collections, but they do follow a set of “best practices” developed to keep belongings physically unchanged for as long as possible.[3] However, some Native perspectives understand belongings to have a natural life cycle that physical preservation interferes with.

“For example, everything has a life, and it serves a purpose. And when that life is over, it’s meant to go back to the earth. In Western science, it’s the same idea of entropy or the law of conservation of mass and energy. We have it, too, in our Navajo ways of thinking. And so, the idea of saving something forever is impossible, but that’s what we’re attempting to do by curating these pieces and keeping them here.” – Venancio Aragon

Diné (Navajo) Chief’s Blanket, 1800-1850. Wool, dye. 58 × 71 15/16 in. (147.3 × 182.8 cm). SAR.1999-2-121. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.
Diné (Navajo) Blanket, 1850-1860. 58 x 76 in. (147.3 x 193 cm). IAF.T46. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.
Diné (Navajo) Blanket, 1865-1875. 52 3/4 × 45 in. (134 × 114.3 cm). IAF.T62. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.

Image Caption: SAR.1999-9-121, IAF.T46, and IAF.T62: These three pieces are referred to as “chief blankets”. SAR.1999-9-121 was made between 1800 and 1850, making it one of the earliest chief blankets. Though chemical treatment physically preserved it, maybe for over two-hundred years by now, it also prevents it from taking part in the natural cycle that Aragon describes.


Despite pesticide residue being a widespread issue in museum collections, Laura Elliff Cruz does not remember it being widely addressed or discussed prior to the 2005 publication, Old Poisons, New Problems: A Museum Resource for Managing Contaminated Cultural Materials. As it is discussed more, museums and communities have difficult conversations about the best way forward.

“A lot of communities who have visited museum collections are just used to knowing. People who go to collections all the time and review collections, they’re aware of past pesticide treatments. But there may be people from smaller communities that have never heard of this. So, to explain things verbally in a transparent, friendly, and welcoming way about this historical treatment of their items–it’s a very hard conversation.” – Laura Elliff Cruz

Pesticide treatment has particularly troubling implications regarding repatriation.[4] It is important that museums research the history of pesticide use in their collections and institutions to be able to fully inform communities when repatriated belongings may be contaminated, which is required by NAGPRA.[5] It is the community’s decision how repatriated belongings with toxic residues should be handled.  

Museums should consult with affiliated tribes prior to any testing, as testing can be invasive or otherwise inappropriate. The type of chemical, the levels of exposure, and the tribal end use for repatriated belongings all affect what is suitable. However, there may be approaches that mitigate those risks while allowing end use. For example, some museum professionals are researching the ability of some native plants to keep soil clean at reburial sites.[9]

Diné (Navajo) Shoulder blanket, woman’s, 1870-1880. 35 13/16 x 51 3/16 in. (91 x 130 cm). IAF.T423. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.
Diné (Navajo) Saddle blanket, 1880-1895. 36 x 55 in. (91.4 x 139.7 cm). IAF.T27. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.
Diné (Navajo) Blanket or manta, 1870-1880. 40 3/16 x 61 in. (102 x 155 cm). IAF.T355. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.

Image Caption: IAF.T423, IAF.T27, and IAF.T355: These textiles are not subject to NAGPRA, but it is still important that the life and knowledge they hold be accessible to Native artists and communities. Prior to this exhibit, the catalog record described the weave of IAF.T27 simply as “twill.” Consulting with Aragon, IARC staff  learned that the crisscrossing patterns are tapestry weave, while the solid red portions are likely diamond twill.


Venancio Aragon reflects that interacting with chemically treated textiles can be a “double-edged sword.” Pesticides successfully physically preserved textiles when other methods of preservation were less available, and he appreciates being able to view older pieces. However,

“On the other hand, I think it’s a little discouraging to not be able to interact with the textiles fully as one might want as a weaver. To touch and feel the textures of the wool and yarns used, to get close. Many Navajo weavings have a certain smell to them that gives clues to the wool processing methods. For example, if the wool was washed before spinning or after the yarn was spun there may remain a scent of lanolin. Many Navajo people today will smell a textile to gather information from the piece by their senses. The smell of textiles may trigger memories and information a weaver has and that’s one detriment to pieces that have been treated, we don’t get to fully interact with them.”

Native and non-Native conservators are working to find effective and feasible treatments, but arsenic residue is difficult to remove from belongings without affecting them physically.[10] Tribal communities may decide to leave the residue on the material.

IARC tested textiles using an X-ray fluorescence (XRF) testing technique and had surfaces evaluated by an industrial hygienist. The results showed that the arsenic residue only cross-contaminated between different surfaces with repeated exposure over long periods of time. Handwashing before and after handling helps to minimize potential risk. The IARC provides Tyvek coats and nitrile gloves to visitors who interact with the textiles. While these safety precautions at the IARC were once required, they are now “recommended.” The IARC provides safety information, and Native artists and communities decide for themselves how to interact with the textiles.

Diné (Navajo) Blanket, c. 1850. 49 3/16 x 79 1/8 in. (125 x 201 cm). IAF.T363. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.
Diné (Navajo) Blanket, 1870-1880. IAF.T466. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.

Image Caption: IAF.T363 and IAF.T466 are a type of textile commonly referred to as “slave” blankets.[11] When Venancio Aragon and his mother Irveta Aragon viewed IAF.T466, they told personal stories of captured women during this period in history.

“When we as descended peoples associated to these pieces-through our lineages, oral histories and family histories view and interact with them, we add humanistic elements to their interpretation. The term “slave blanket” doesn’t really mean much until the context of history and lived experience is talked about…it’s the meshing of knowledge sources that provides more of a humanistic way of looking back at what our ancestors created. Pieces like the slave blankets become alive and give glimpses to us today of what our ancestors lived through and endured.” – Venancio Aragon

The blankets referred to as “slave” blankets were woven by Diné (Navajo) women enslaved in Spanish colonial households and forced to weave.[12] Their captors wanted textiles that met market demands, so the weavers incorporated design and color elements from Rio Grande (Southwest Hispanic) textiles.[13] Using an upright loom, the weaver wove a blanket in two long, separate pieces, then joined them.


Today, the IARC uses Integrated Pest Management (IPM) to prevent pests. Vulnerable materials may be kept in air-tight containers, and employees monitor pest traps to prevent infestations. Other forms of preventive conservation, like regulating humidity and temperature, prevent physical deterioration. However, the IARC integrates Indigenized forms of care outside of these practices.[14] For example, at the IARC, Native communities may feed belongings, or take them outside for fresh air and sunshine, and special housing can be made if air-tight containers are not appropriate.

Typically, textiles are rolled up, sealed in plastic sheeting, and housed in compact shelving. This minds the physical integrity of the textiles and maximizes storage space, but makes staging and viewing them more difficult. With the added barrier of chemical treatment, it is harder to view textiles than other parts of the collection like pottery and jewelry. Venancio Aragon states that:

“—at the time I feel sadness. When researchers or the public are present in the IARC, it’s lit up. There are people here and there is life here, but when we leave and the lights all turn off, it makes me think of all the beautiful objects and how they have to be alone in the dark and nobody is around to see them and interact with them….they are stored and are away from their communities. I think of Indigenous children who were taken from their communities and were isolated among Western people. The pieces in the IARC become items and numbers.”

This is one reason that it is so important that the collection be used and accessed. Laura Elliff Cruz reflects that:

“This collection is a living, breathing collection, and it’s important for our collection at [IARC] to be a working collection…it’s so important when you get that gasp when you walk in and some people are just connecting to their family history, or to their community, and sometimes, you know, a lot of these art forms may be lost, so I think just, a collection, to handle keeps it alive and not static, and to be utilized is really important. You can feel that presence.”

Diné (Navajo) Rug, Theresa Bowman (Diné (Navajo)), 1942. 53 9/16 x 35 1/16 in. (136 x 89 cm). IAF.T396. Photograph by Addison Doty. Copyright 2009 School for Advanced Research.
Diné (Navajo) Rug (detail), Theresa Bowman Diné (Navajo), 1942. 53 9/16 x 35 1/16 in. (136 x 89 cm). IAF.T396. Photograph by Addison Doty. Copyright 2009 School for Advanced Research.
Diné (Navajo) Saddle blanket or rug, 1920-1940. 33 7/8 x 51 15/16 in. (86 x 132 cm). IAF.T507. Photograph by Addison Doty. Copyright 2022 School for Advanced Research.
Diné (Navajo) Rug, 1960-1970. 36 in. (91.4 cm). IAF.T735. Photograph by Addison Doty. Copyright 2009 School for Advanced Research.

Image Caption: These textiles were created using a diamond twill technique. IAF.T396 was made by Theresa A. Bowman (Diné), sister-in-law of the inventor of the multiple heddle technique Kathryn Peshlakai Arviso (Diné). The complex technique weaves a different pattern into the opposite side, seen in the picture here. Weaver Roy Kady (Diné) commented in the IARC catalog that this technique is very complex, requiring 21 heddles to accomplish, and Sarah H. Natani is one of the few weavers who knows how to do it.


Decolonizing collections management in museums entails addressing the harmful aspects of colonial care, including the dangers of pesticides, as well as decentering Eurocentric ideas of what it means to care for collections.[15] Although established as colonial institutions, museums and cultural centers can honor obligations to Native people and be a resource:

 “…but it’s places where Native peoples can come and they can reconnect with, perhaps, parts of their history that have been fragmented, or tattered, or decayed from the effects of colonialism. And to rebuild those techniques, or teachings, or knowledge, or whatever information you can extract from those objects.” – Venancio Aragon

The textiles at the IARC are available for Native artists and communities to interact with. The IARC is open to tribal community groups, tribal leaders, elders, cultural leaders, students, and artists who wish to study the collections.  The IARC offers tours and hands-on programming at no cost to tribal members and to children attending Indian schools. To learn more, visit https://sarweb.org/iarc/native-community


My sincere thanks to Venancio Aragon, Irveta Aragon, and Laura Elliff Cruz for their invaluable insights and contributions to this project.


[1] Willink, Roseann Sandoval., and Paul G. Zolbrod. (1996). Weaving a World: Textiles and the Navajo Way of Seeing. Santa Fe, NM: University of New Mexico Press.

[2] Doerring, Melina. (2003). “A Survey of Historical Pesticide Use at MIAC & MOIFA: A Manual for Museum Staff.” Santa Fe, NM: Museum of New Mexico.

[3] Bangstad, Torgeir Rinke. (2022). Pollution and Permanence: Museum Repair in Toxic Worlds. Museums & social issues (no. ahead-of-print), 1–15. Retrieved from https://doi-org.du.idm.oclc.org/10.1080/15596893.2022.2083356

[4] The SAR/IARC is in compliance with NAGPRA legislation and strives to ensure that claims are resolved in a timely and respectful manner.

[5] Odegaard, Nancy. (2019). Pesticide Contamination and Archaeological Collections: Contextual Information for Preparing a Pesticide History. Advances in archaeological practice: a journal of the Society of American archaeology, 7(3), 292–301. Retrieved from https://doi.org/10.1017/aap.2019.28

[6] Makos, Kathryn A. (2001). Hazard Identification and Exposure Assessment Related to Handling and Use of Contaminated Collection Materials and Sacred Objects. Collection Forum 17(1-2).

[7] Sadongei, A. (2001). American Indian Concepts of Object Use. Collection Forum 17(1-2), 113-116.

[8] Caldararo, N., Davis, L., Palmer, P., and Waddington, J., (eds.). (2001). “The Contamination ofMuseum Materials and the Repatriation Process for Native California: Proceedings of a Working Conference at the San Francisco State University, 29 September to 1 October 2000”, Collection Forum 16(1-2); Odegaard, Nancy. (2001). Methods to Mitigate Risks from Use of Contaminated Objects, Including Methods to Decontaminate Affected Objects, Collection Forum 17(1-2), 117-121.

[9] McAdams, Melodi and Courtney Coyle. (January 27, 2023). Emerging Best Practices in Contamination: A Tribal Perspective [NAGPRA Community of Practice Call]. University of Denver. https://mediaspace.du.edu/media/Emerging+Best+Practices+in+ContaminationA+A+Tribal+Perspective/1_y9ttn9mq/276861963

[10] Anderson, Jae R. (2014). Coping with Arsenic-Based Pesticides on Dinè (Navajo) Textiles. [Doctoral Dissertation, University of Arizona]. ProQuest Dissertations Publishing. Retrieved from https://du.idm.oclc.org/login?url=https://www.proquest.com/dissertations-theses/coping-with-arsenic-based-pesticides-on-dinè/docview/1620743809/se-2; Cross, Peggi S., Nancy Odegaard, and Mark R. Riley. (2010). Lipoic Acid Formulations for the Removal of Arsenic and Mercury from Museum Artifact Materials. Journal of archaeological science, 37 (8): 1922–1928. Retrieved from https://doi.org/10.1016/j.jas.2010.02.018

[11] Sources using term “slave blanket” attribute it to H.P. Mera’s pamphlet “The Slave Blanket”, published through the Laboratory of Anthropology in 1938. It is unclear if Mera coined the term or if it was commonly in use before the pamphlet was written.

[12] Brooks, James F. (2002). Captives and Cousins: Slavery, Kinship, and Community in the Southwest Borderlands. Chapel Hill, NC: University of North Carolina Press, p. 239. Retrieved from http://du.idm.oclc.org/login?url=https://heinonline.org/HOL/P?h=hein.amindian/capcousb0001&i=1

[13] McLerran, Jennifer. (2018, March 17). ATADA Foundation Update – Museum of Northern Arizona: Stabilization of Navajo Slave Blanket (E5514). Retrieved from https://atada.org/atada-blog/2017/10/8/1fcmj4t75wbzuk4ifo3jnxbzr6ff47-cd9dr-3yn4g

[14] Clavir, Miriam. (2002). Preserving What Is Valued: Museums, Conservation, and First Nations. Vancouver, CA: UBC Press. Retrieved from https://ebookcentral.proquest.com/lib/du/detail.action?docID=3412022

[15] Odegaard, Nancy, and Alyce Sadongei. (2005). Old Poisons, New Problems: a Museum Resource for Managing Contaminated Cultural Materials. Walnut Creek, CA: AltaMira Press.