By: Lauren Nowakowski 

Department of Anthropology, University of Texas at San Antonio 

Introduction 

Graffiti is an art form that can be found in various contexts and cultures all around the world, beginning in the ancient past and continuing into the present. Graffiti is broadly defined as an “artistic expression conducted as secondary additions to surfaces in which it did not initially belong” (Lovata and Olton 2016:13; Nowakowski 2023:15). The ancient Maya are one of these cultures who produced graffiti. Ancient Maya graffiti is found in a variety of contexts with highly variable content, making its study rich in providing insights into Maya life. Historically, ancient Maya graffiti has been an understudied topic within Maya archaeology, but with new discoveries, re-analysis of previously encountered instances, and technological advancements in documentation methods there is a constant growth in the ancient graffiti scholarship. The focus of this paper is on different documentation methods, through a case study of Structure A-5-2^nd which is located in the main acropolis of El Castillo at Xunantunich in Belize. The techniques examined include Reflectance Transformation Imaging (RTI), hand mapping, Mylar tracing, and the conversion of these methods into digital line drawings. These methods are analyzed by identifying the advantages and disadvantages of each technique, and how these differences impact researchers in variable field settings. This article is a condensed version of the author’s MA thesis (Nowakowski 2023).  

Structure A-5-2^nd  

Xunantunich is an archaeological site located within the Mopan River valley of Belize, and contains numerous instances of ancient Maya graffiti located within a variety of contexts. Structure A-5-2^nd contains two vaulted galleries with the southern facing gallery the focus of this study. The southern facing gallery of Structure A-5-2^nd contains two rooms with large benches (referred to as Room 1 and Room 2) and a connecting exterior wall (Figure 1). Together these two rooms and exterior wall contain over 500 graffiti elements that were incised and painted into the plastered walls, doorjambs, and benches. The graffiti analyzed in this study are all incised into the walls of Room 2 in Structure A-5-2^nd. The graffiti have previously been organized into seventeen different categories of imagery that include: zoomorphic features, anthropomorphic features, architectural features, deity figure, hieroglyphs, markings, unknown imagery, ritual scenes, decorated shapes, line-based elements, and simple shapes (Brown et. al. In Press; McCurdy et al. 2018:188). Due to a variety of factors including the large clustering of graffiti, repeated designs, skill of execution and location within the site’s main acropolis, the graffiti assemblage from Structure A-5-2^nd has been interpreted by Brown and colleagues to have performed as a space of specialized instruction for young acolytes (Brown et. al. In Press; McCurdy et al. 2018). The large quantity of graffiti within Structure A-5-2^nd is unusual. This makes the space unique when compared to spaces containing Maya graffiti found in other locations, but perfect for providing systematic observations about documentation methodology that can still be useful to other areas.  

Figure 1: Photogrammetry model of Room 1, Room 2, and the Exterior Wall from the southern gallery of Structure A-5-2^nd (model by Neil Dixon) 

Documenting Ancient Maya Graffiti 

The documentation techniques used to record ancient Maya graffiti have been ever evolving. Some of the techniques that have been incorporated include rubbing, photography, laser scanning, photogrammetry, Reflectance Transformation Imaging (RTI), Mylar tracing, and hand mapping. The growing technological advances along with the broad array of applicable techniques are what underscores the need for researchers to be able to identify and compare different recording methods in order to choose the best approach for documenting graffiti in their specific setting. When documenting the graffiti in Room 2 from Structure A-5-2^nd, three techniques were chosen that differ in terms of equipment needed, skills required, funds, and site-specific restraints and requirements. The techniques applied to Structure A-5-2^nd are RTI, hand mapping, and Mylar tracing. These three techniques were chosen for this comparative study as they are three common techniques used when documenting graffiti, but they each require vastly different skills and equipment. Their unique differences thus allow for conclusions to be drawn as to how one technique might meet the situational needs of a researcher documenting ancient Maya graffiti better than others.  

Reflectance Transformation Imaging (RTI) 

RTI is a digital modeling technique conducted with a DSLR camera that captures ideally 48 images of an object with the light source in each image taken at various oblique angles (Earl et al. 2010; Malzbender et al. 2001). This process requires a DSLR camera, a strong moveable light source, string, scale, tripod, remote flash trigger, two reflective spheres, and a computer. The photographs are processed through the RTI modeling software Relight, which results in the creation of an RTI model that can be manipulated to study the surface texture of an object with a moveable light source, similar to a raking light effect in photography. All of the RTI models of the graffiti from Structure A-5-2^nd were done by Neil Dixon (Dixon et al. 2019). Once the model is created it can be analyzed away from the field. In order to digitize the graffiti from the model screenshots can be taken of specific graffiti which can then be brought into Adobe Illustrator. The researcher can then trace the incised graffiti lines on Illustrator while also accessing the model to study the lines by manipulating the light source, thus creating a digital line drawing. 

Hand Mapping  

Hand mapping is a technique that involves the creation of scaled maps on graph paper done in the field. The tools required include graph paper, pencils, and a plastic grid or string lines attached to the wall to measure from. For this study, I attached a piece of clear plastic to the plastered walls that included a 1 cm by 1 cm grid drawn on with Sharpie (Figure 2). The graffiti was then drawn at a scale of 1 cm to 1 cm on the corresponding graph paper. Each square on the graph paper corresponded with the same 1 cm by 1 cm square on the plastic grid attached to the wall. The resulting line drawing on the graph paper would later be scanned and brought in to Adobe Illustrator where it would be digitized to create a digital line drawing.  

Mylar Tracing 

Mylar tracing involves tracing by hand on the surface being recorded. This method requires a transparent material attached to the wall with small nails, the incised graffiti lines beneath are then traced with a sharpie (Figure 3). For this study a plastic material called Mylar was attached to the plastered walls. Once the graffiti is traced, a to-scale line drawing of the graffiti has been created, which can then later be scanned on to the computer. Once scanned, the line drawing can be digitized in Adobe Illustrator.  

Applying the Techniques 

Only certain graffiti were chosen for documentation in this comparative analysis. The graffiti chosen came from Room 2 of Structure A-5-2^nd, as Room 1 had already been extensively documented during the 2016 field season when it was first exposed (McCurdy et al. 2018). For this study, I chose 14 areas on the walls of Room 2 based on their level of complexity, location within the rooms, and different densities of graffiti elements ranging from 1 to 17 graffiti total. For each of the 14 areas, I began by conducting hand mapping and then repeating the documentation process with Mylar tracing and RTI mapping. The resulting data from each method was then placed into Adobe Illustrator in order to create digital line drawings (Figure 4). It is necessary to note how my skill as an illustrator is reflected in my results, and that other researchers with distinct strengths and weaknesses may take more or less time to do the same tasks. By mapping these 14 areas I was able to observe the complexity of the graffiti, its location relative to other surfaces within the space, equipment required, time required to document in the field and in subsequent digitization, problems encountered with the techniques, researcher biases that may impact documentation, and situations in which specific techniques might be more effective or ineffective. Through collecting these observations for RTI, hand mapping, and mylar tracing, I was able to clearly compare the techniques across a wide variety of factors. 

Figure 4: Visualization of the digitization process. The image on the left is the hand drawn map done on graph paper. The image on the right is the digital illustration created in Adobe Illustrator from the hand drawn graph paper map. 

Results 

Each of the three documentation techniques proved to have certain advantages and disadvantages when applying them to the 14 mapped areas. In order to clearly articulate the strengths and weaknesses of each technique in regard to how they might benefit researchers in different contexts I will compare them within the following domains: preservation concerns, logistical considerations, efficiency, accuracy, applicability in small spaces, and degree of engagement with the graffiti. The results of the time taken to document each method is displayed in Table 1, and the total number of graffiti elements recorded through each technique is displayed in Table 2. 

Table 1: Comparison of the time taken to document each method 

Map Label	Time taken to document through hand mapping (in minutes)			Time taken to document through RTI (in minutes)			Time taken to document through Mylar tracing (in minutes)
	In Field	Digitized	Total	In Field	Digitize	Total	In Field	Digitize	Total
Map 1	60	32	92	62	44	106	7	25	32
Map 2	120	57	177	62	65	127	20	29	49
Map 3	80	60	140	62	110	172	25	38	63
Map 4	95	90	185	62	146	208	27	87	114
Map 5	90	80	170	62	96	158	X	X	X
Map 6	100	87	187	62	240	302	X	X	X
Map 7	20	13	33	62	23	85	4	17	21
Map 8	38	38	76	62	61	123	15	28	43
Map 9	51	70	121	62	109	171	18	30	48
Map 10	9	12	21	62	17	79	3	6	9
Map 11	110	107	217	62	91	153	70	62	132
Map 12	26	28	54	62	48	110	14	14	28
Map 13	65	45	110	62	70	132	26	25	51
Map 14	51	80	131	62	90	152	20	40	60
Total	915	799	1,719	868	1,210	2,078	249	401	650

Table 2: Comparison of the number of graffiti elements recorded through the 3 documentation methodologies 

Map Label	Hand mapping Elements Recorded		RTI Mapping Elements Recorded		Mylar tracing Elements Recorded
	#’s of Elements Recorded	Total Elements Recorded	#’s of Elements Recorded	Total Elements Recorded	#’s of Elements Recorded	Total Elements Recorded
Map 1	1, 12, 21	3	1, 12, 19, 21	4	1, 19, 21	3
Map 2	1	1	1	1	1	1
Map 3	1, 2, 3, 8	4	1, 2, 3, 27, 8, 26	6	1, 2, 3, 8	4
Map 4	13, 62, 63, 79, 60, 59, 58, 14, 53, 55, 56, 52, 93	13	13, 62, 63, 79, 61, 60, 59, 58, 14, 56, 52, 93, 57, 53, 55, 54	16	13, 62, 63, 79, 61, 60, 59, 14, 58, 56, 52, 93	12
Map 5	1	1	1	1	X	X
Map 6	7, 8, 14, 6, 24, 13, 11, 10, 12, 27	10	5, 29, 7, 8, 14, 25, 6, 27, 24, 13, 32, 30, 10, 11, 9, 12	16	X	X
Map 7	2, 13	2	2, 13	2	2, 13	2
Map 8	6	1	6	1	6	1
Map 9	17, 12, 13, 14	4	12, 13, 14, 15, 17	5	17, 12, 13, 14	4
Map 10	9	1	9	1	9	1
Map 11	1	1	1	1	1	1
Map 12	25, 21, 24, 29, 89	5	25, 21, 22, 24, 29, 89	6	21, 25, 24, 89, 29	5
Map 13	44, 46, 47, 49, 90, 48, 45, 50, 51, 91	10	44, 45, 46, 47, 48, 49, 50, 90, 91, 51, 100	11	44, 45, 46, 48, 47, 49, 50, 51, 90, 91	10
Map 14	7, 9, 10, 77, 64, 65, 76	7	64, 76, 7, 10, 9, 77, 65	7	64, 76, 7, 65, 9, 77, 10	7
Total:		63		78		51

Logistical Considerations and Efficiency 

Each of the methods required documentation in the field and later processing away from the field. Once exposed, graffiti should be documented during the field season as the longer the plaster is exposed the more likely that the plaster will degrade. Meaning that time taken, and experience required, are both necessary concerns for a researcher determining their desired documentation technique. Mylar requires the least amount of set up, training, and time, as one only needs to attach the Mylar to the surface being recorded and then trace the incised lines. Mylar took the least amount of time, totaling only 650 minutes, with both RTI and Hand mapping taking nearly double the time (Table 1). While this method is easy and quick, the researcher may not have the Mylar material readily available in their field setting if they unexpectedly uncover graffiti. Hand mapping is the most accessible method, along with photography, as researchers at field sites would have all of the tools required to conduct it. Hand mapping though is more time consuming than Mylar, and would take a considerable amount of time if the researcher is recording a large amount of graffiti. RTI, requires the most amount of training and additional tools in order to accurately conduct it. While the processing software is free, the in-field documentation process would require a camera, laptop, moveable light source, and small reflective spheres, making this a much costlier endeavor. While RTI requires the most training and tools it is the most accurate of the methods, making it the highly advisable choice for researchers. If RTI is not possible upon first exposure, then it is best to conduct Hand mapping and Mylar tracing, with RTI done at a later date if possible. 

 Preservation concerns 

Of the techniques, RTI was the least invasive, as it required minimal contact with the surfaces being documented. Hand mapping and Mylar tracing both required significantly more contact with the surface, as the hand mapping required the attachment of a clear plastic grid and the Mylar mapping required the Mylar to be attached to the wall. When attaching these plastic pieces to the surfaces of the wall they were attached with small nails to areas that had damaged plaster and/or did not have graffiti present. Therefore, if a researcher is documenting graffiti located on a delicate surface a less invasive technique such as RTI would be preferred above Mylar tracing or hand mapping. 

Accuracy 

Accurately depicting the graffiti during recording is a necessary consideration when deciding which method is most appropriate for documentation. While Mylar took the least amount of time, this meant a tradeoff in terms of quality when compared to RTI and hand mapping. The lines from Mylar were the thickest and least accurate due to the use of Sharpie and difficulties in seeing the incised lines when tracing through the Mylar plastic. Mylar also recorded the least amount of elements and details when compared to RTI and hand Mapping. In the comparison of graffiti elements recorded across the three techniques RTI resulted in the most detailed depiction with Mylar the least detailed (Table 2). Hand mapping was the second most accurate method, as it resulted in high quality line drawings of graffiti elements that was easy to digitize. The results of this study indicate that the line drawings made using RTI resulted in the highest level of detail and accuracy (Figure 5). RTI was able to record the highest level of detail, and allowed for continual inspection due to the digital availability of the RTI models. Both Mylar tracing and hand mapping can only be inspected in the field, or through use of another technique such as RTI, Photogrammetry, or photography.  

Figure 5: Comparison of a close-up section of line drawn graffiti elements 92, 59, 58, 60, 14, and 56 from map 4 done across the three techniques demonstrating differences in detail 

Availability in Small Spaces 

Which technique will work for researchers also depends on the size of the space in which one is recording. Depending on space, only one researcher may fit, meaning that limited materials can be brought in. This could prolong the time required for recording, or limit the possibility of incorporating techniques that require large tools. In terms of RTI, recording in spatially confined areas or areas where the graffiti is near a wall or unexcavated area can be difficult, this is due to the inability of the light source to conduct a full rotation during the photo capturing process before building the model. Hand mapping and Mylar tracing can both be conducted in confined spaces as they only require one individual and a few small materials.  

Creating Maps to Scale 

In regards to scale, hand mapping and Mylar tracing are both inherently scaled. RTI data can be scaled, but it requires a scale placed in the models or added in at a later date. Hand mapping and Mylar tracing, as hand documented techniques, do not have to worry about visual warping, which is one of the major concerns with photography conducted in tight spaces or at extreme angles. The inherent scale of hand mapping and Mylar tracing makes it highly appealing to researchers.  

Degree of engagement with Graffiti   

While each of these three techniques begin in the field, they require different levels of engagement. Hand mapping and Mylar tracing both require in depth examination of the graffiti element when recording them. This is due to the researcher needing to determine which of the incised lines are a part of the graffiti when creating the map. Close inspection also allows for researchers to engage with other aspects of the graffiti such as the spatial arrangements and height from the floor surfaces. While RTI also requires in field examination it does not require in depth engagement with the graffiti by the researcher. The semi objective quality of RTI is what can limit the engagement, as the researcher recording in the field does not need to determine which lines are a part of the graffiti as the RTI records everything on the surface in totality. Also, the person engaging with the RTI models may not have been the person recording the graffiti in the field. Deeply engaging with the graffiti in context allows a researcher a more holistic understanding of the space and more nuanced interpretations of the artist working in that space.   

Conclusions 

When documenting ancient Maya graffiti, it is important to recognize the advantages and disadvantages each technique contains, and how the resulting digital line drawings will be used in future studies. The technique chosen for recording will impact how the data is collected, interpretations, and how the data is displayed. As studies surrounding ancient Maya graffiti continue to grow, the need for accurate and effective documentation will only increase. In order to ensure graffiti is documented to the best of its abilities it needs to be documented accurately while also containing key information regarding spatial analysis and context. By seeking out the best documentation method for each researcher’s specific situation, the accuracy of ancient Maya graffiti will be ensured, helping to preserve graffiti for future researchers and broader publics interested in these remarkable artistic works and the ancient artists who created them.   

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References 

Brown, M. Kathryn, Leah McCurdy, and Jason Yaeger  

In Press Chamber of Secrets in Xunantunich. In Maya Materialization of Time: Mythic History and Ritual Order in the Ancient Maya World, edited by David Friedel, Arlen Chase, Anne Dowd, and Jerry Murdock. University Press of Florida, Gainesville. 

Dixon, Neil, M. Kathryn Brown, and Leah McCurdy  

2019 RTI Photography Part of a Greater Whole in Archaeological Documentation Methodology. In Archaeological Method and Theory in Practice, Part II. 

Earl, Graeme, Kirk Martinez, and Tom Malzbender  

2010 Archaeological applications of polynomial texture mapping: analysis, conservation and representation. Journal of archaeological science 37(8):2040–2050. DOI:10.1016/j.jas.2010.03.009. 

Lovata, Troy R., and Elizabeth Olton (editors)  

2016 Understanding Graffiti: Multidisciplinary Studies from Prehistory to the Present. Routledge, New York. 

McCurdy, Leah, M. Kathryn Brown, and Neil Dixon  

2018 Tagged Walls: The Discovery of Ancient Maya Graffiti at El Castillo, Xunantunich. Research Reports in Belizean Archaeology 15:181–193. 

Malzbender, Tom, Dan Gelb, and Hans Wolters  

2001 Polynomial texture maps. pp. 519–528. SIGGRAPH ’01. ACM. 

Nowakowski, Lauren 

2023 Methodological Approaches to Recording Ancient Maya Incised Graffiti: A Case Study From Structure A-5-2nd at Xunantunich. Available from Dissertations & Theses @ University of Texas – San Antonio; ProQuest One Academic. (2819907456). https://login.libweb.lib.utsa.edu/login?url=https://www.proquest.com/dissertations-theses/methodological-approaches-recording-ancient-maya/docview/2819907456/se-2