Painting an Olive Jar Neck Sherd from the Luna Site in Pensacola, FL

Last month, I discussed some useful tips on how to paint 3D printed plastic objects. Today, I will walk you through the painting process using an olive jar neck sherd from the Luna site. The sherd was one of the defining artifacts that helped UWF archaeologists recognize and establish the significance of the site. Below is my step-by-step guide on how to paint this specific artifact using the equipment and tips I outlined in my previous post.

  1. painting-stationHere is my painting station, equipped with the colors I use for this artifact (minus two that I added in), paint brushes, paper towels, my “palette,” and a water cup. 
  2. I start by adding a layer of unbleached titanium over the whole object.first-layer-ubt-mariana
  3. Then, I mix some paints to create the reddish color of the entire vessel. I use red and yellow to create a salmon color and add bits of Unbleached Titanium and Raw Sienna. I use the dabbing technique to create texture.

    1. Here is a close-up of the texture.
      second-layer-detail-mariana
    2. Here is the entire second layer.
      second-layer-whole-mariana
  4. colors-used-for-gray
    Colors used for gray.

    I mix the colors I use for the gray sides of the artifact. I obviously do this by mixing white and gray and then paint one layer on the sides. For a second layer of gray, I add a little bit of Raw Umber to the mix, which makes it slightly more brown. When I layer it on top of the light gray color, it creates depth and texture. There is also a line of gray at the bottom of the artifact.

  5. I do something similar to the entire object now. I add a little bit of grays and browns over the entire object to match the various tones and colors the artifact has in real life. I do this using a mix of dabbing and dry brush techniques and I try to be gentle and light about applying this layer.
  6. The final touch is to add a black detail towards the bottom corner of the concave side.
    black-feature
  7. This is the final product:

The final product is definitely not perfect, but it will do! Painted models, such as the olive jar neck sherd, can be implemented in educational demonstrations in classrooms, out in the field, in museums, or anywhere where archaeologists are able to interact with the public. I really hope that you enjoyed these blog posts about painting plastic artifacts and found some useful information. As always, feel free to respond with any questions or feedback.

Happy painting!


Mariana Zechini is a graduate student at the University of West Florida. She received her B.S. in Anthropology at Virginia Commonwealth University in 2014 and has four years of experience in 3D scanning archaeological materials. Her thesis focuses on analyzing stable isotopes from human remains from a medieval cemetery site in Berlin, Germany.

Bringing Archaeology and 3D Modeling to the K-12 Classroom

Many archeologists, as part of their public outreach efforts, see the recent movement to bring science and math based curriculum into classrooms as an opportunity to introduce both teachers and students to archaeology and anthropology. This trend has also caused schools and programs to reach out to archaeologists and other scientists to present to their students. However you end up standing in front of thirty 5th graders, there are some things that will help you achieve your goals and survive to see another invitation extended to you.

I would argue that archaeology is uniquely suited to classroom presentations in that it covers every subject being taught in today’s schools, especially when 3D modeling is included, and is an inherently hands on and accessible science. In order build an easy to use guide for people interested in bringing 3D modeling and archaeology to public education I have drawn on my knowledge of the public education standards and how to best cooperate with public school teachers, gained by five years experience in a classroom. Though I will focus mostly on archaeological modeling and K-12 education in this post, all of the material covered here is applicable to all fields of anthropology, all subfields of archaeology, and really any field of science.

Getting into the classroom

The two biggest things to remember when presenting in a kindergarten through 12th grade education setting is time and flexibility. Time is everything to a teacher, and even more important to the students. Frustrations about time are not necessarily exclusive to the time you are taking out of their day by presenting. Sometimes it is the time of day you want to come into the class, and sometimes it is the time of year. This is where flexibility comes in. Here are my quick and easy tips to getting a teacher to say yes, and to have them ask you back:

  1. Contact schools you work with and get a school calendar, or join their Facebook page. If you know what is going on at school a teacher will not turn you down because you asked to come and present on field day. 
  2. Know or ask what topic/subject they are covering and explicitly tell the teacher how the material you are presenting matches that. My other suggestion to this is do not concentrate only on science. See the next section for more details on this. 
  3. Bring ALL necessary supplies (including pencils and paper) and make sure to communicate this with the teacher. Also, if you will be using computers, arrive early and make sure everything is in order for the kids to log on.

Standards

All topics taught by a teacher must meet what they call a standard. These standards can include things like teaching a kindergartener that a book has a front cover and a back cover (standard “LAFS.K.RI.2.5”). Before you freak out I’m not proposing that anyone learn the standards, though they are available for your reading pleasure on every state’s education website. Here are the Florida standards for language arts and math by grade level.

standards
Kindergarten standard for reading. (Source: Florida Department of Education)

 

The chart below connects the four main subjects to 3D modeling and printing in archaeology. The great thing about many topics covered within each subject is that they can be taught at almost every grade level, with varying degrees of difficulty of course. Elementary schools, for example, may only have the students classify according to shape, size, and color whereas middle schoolers are capable of predicting the use of an object and classifying based on those observations. Seeing these parallels will save you some time in writing lessons and will increase the variety of grade levels you can present in.

Subject

Archaeological 3D Modeling

Archaeology (all subfields)

Math

– Scale and ratio
– Conversion of standard to metric
– Fractional measurements
– Coordinate grids
– Laying out a unit (Pythagorean Theorem)
– Positive/Negative numbers
– Angles
– Degrees

Science

– Building experimental models
– Classification
– Documenting results
– Geology
– Weather Cycles
– Evolution
– Chemistry (Carbon 14)

History

– Photography for preservation
– Interpreting sites and items
– Understanding context
– Academic research
– Preserving historic items
– Validating sources

Language Arts

– Creative writing prompts
– Argumentative writing about interpretations
– Academic writing prompts
– Report writing
– Critical dissent
– Concise writing through abstracts
This table is only a sampling of the topics that can be taught per subject, I stuck with general ideas because each school district and each state has their own standards that need to be met.

To help clarify, I will expand upon one topic within each subject and choose a grade level to give a better perspective of how they connect to classroom instruction.

Math: Scale and Ratio

minicatapult1
Min catapults in a math class for exploring math and historic technology. Full article here. (Image by 3dprint.com)

In Florida, most 6th grade students are beginning to learn how to work with ratios and scale modeling. A possible lesson connection could be scaling a building within modeling software so that it could be displayed and explored in a museum by smaller kids. This is a hands-on math intense topic that helps others and has real world applications.

Science: Classification

Elementary students begin to classify objects very early on, by shape and size, as early as kindergarten. Using 3D printed lithic points and pottery students could work on their classifying skills while also handling what would otherwise be fragile artifacts.

magnetized-model-2
For further reading on the power of these models to communicate context, see this post. (Image by Mariana Zechini)

History: Understanding Context

Holding an object only seen in pictures before can often be revolutionary. Changing a person’s perspective and understanding of an item. High Schoolers begin writing research papers early on in their freshmen year, and often write about things they have only seen in books. Physically touching a cannonball that shattered on a tree, like the one printed by UWF students Janene Johnston and Mariana Zechini, can add context to the tree, the cannon ball, and the person who surely escaped death.

Language Arts: Writing

Amazingly, this is often forgotten by archaeologists and yet comprises a large percentage of what we do. Academic writing and writing an opposing critique are skills they will need as they move into college, something we as archaeologists and scientist are painfully aware of. Archaeologist have a unique relationship with journaling and note taking, a skill that many take for granted.

 

By providing some general examples and simple tips, I have given those that desire to bring 3D modeling into a classroom some tools to access the world of education standards. Because this is only a starting point, if you are an archaeologist hoping to do some public outreach or a teacher looking to give some of your standards a new spin with real world applications, please share if you have ideas of your own.

 


Elizabeth Chance Campbell is a Master’s student at the University of Central Florida and will be defending her thesis, on an 1866 watermill, in the spring. She worked in a low income middle school for five years where she taught students with learning disabilities before moving to Georgia, where her wife is stationed in the Air Force. She hopes to take her experience as an educator and as an archaeologist to the next level by creating lessons that can be incorporated into classroom settings with students of all levels.

Painting the Past: Using Paint to Bring Plastic Artifacts to Life

Scanning and printing in 3D has many applications to the world of archaeology and one of the greatest is its utility in public archaeology demonstrations. However, because plastic models are usually printed in one solid color and are mostly hollow to speed up the printing process, the result does not look or feel much like the original artifact beyond its general shape. To remedy one of these disadvantages, we paint 3D printed models at the University of West Florida. We do this to make the artifact look more realistic and to create a more intimate relationship between the viewer and the artifact. By painting plastic artifacts, we allow the viewer to better understand the object and how it looked during use, after excavation, or following conservation.

mariana-painting
Here, I am painting a case shot from the Natural Bridge Battlefield Historic State Park. My station includes a variety of paintbrushes, acrylic paints and lots of paper plates, cups, and towels. (Image by author)

After I started painting models at the Virtual Curation Laboratory at Virginia Commonwealth University, under Dr. Bernard Means, I began 3D printing and painting for Dr. Kristina Killgrove and the Archaeology Institute at the University of West Florida. Along with some other graduate students, we have painted various types of artifacts from different sites, including hominin and animal bone. Below is a list of equipment needed for painting and some tips I have found useful throughout my experience. Additionally, I have included a step-by-step guide to painting, using an olive jar neck sherd from the Luna site.

homo-naledi-skull
This is a printed homo naledi skull from the Rising Star Expedition led by Lee Berger in South Africa. Digital images of bone are online for researchers to download and print. (Image by author)

 

jar-olive-melado
These are just a few of my favorite painted artifacts that I created throughout my time at UWF. Clockwise from left: an Apalachee jar, lead-glazed coarse earthenware, and an olive jar neck sherd. (Image by author)

 

 

Equipment

  1. A variety of brushes. Ideally, you want as many different types of brushes as possible so that you can re-create as many different patterns as possible. I suggest using any variety of skinny, round tip brushes, flat tip brushes, fan brushes, and angled tip brushes in small and large sizes. You will need the skinny, small brushes for detail and the larger flat tip brushes for larger surface areas. I suggest buying a variety pack of 20-30 brushes on Amazon and experimenting with those.
  2. Acrylic paint. My favorite brand to use is Liquitex Basics. If you are not sure what colors you will need, I suggest buying either the 24- or 48-pack of acrylic paint and seeing which colors you use the most. Or you can buy the 4oz tubes of the colors I have found I use the most (I have never needed the hot pink to paint a plastic model):
    1. Yellow Oxide, Titanium White, Burnt Sienna, Ivory Black, Red Oxide, Burnt Umber, Raw Umber, Raw Sienna, and Unbleached Titanium
  3. Paper plates and cups (or whatever you have at your disposal) for palettes and water cups. I usually use a paper plate as my palette and reuse it as much as possible. I do the same with a water cup and paper towels.
  4. Fixative (optional). I have never had a problem with paint wearing off a plastic artifact. However, if you know the object will be handled a lot, it might be useful to buy a can of spray fixative, which sets the paint and prevents it from rubbing off. Alternatively, hairspray can work as a cheap fixative if you’re in a bind.
  5. An open mind! I love painting plastic models because it combines my love of art and my love of the past. I was an art student for one semester, although I was planning to major in photography, not painting. This experience has been useful but is absolutely not necessary. I never thought of myself as a painter (and I still don’t) but keeping an open mind allows me to be more confident in my painting. So do not be afraid to mess up or try new techniques! The worst that can happen is that you have to paint over it and try again.
cannonball-1
Here you can see the different types of brushes that I use and the base coat of Unbleached Titanium I use on models. (Image by author)

Tips & Techniques

Below are some tips and techniques that I have found useful through my experience. These are only suggestions and it would be a good idea to experiment and see what works best for you!

  • I like to paint each object with one coat of Unbleached Titanium. This is an cream color that works as an excellent base coat by covering up the original plastic color and allows the following coats to be richer in color. It is not totally necessary, but if I accidentally miss a spot while painting, this base coat provides a more natural color (depending on the object, of course) rather than solid black, white, or gray, which are usually the colors that I print in.
  • Use different painting techniques! For example, I prefer to dabble rather than paint one even coat all over the object. Dabbling provides texture, which is absolutely necessary when representing artifacts. For example, dabbling helps to create the porous texture that most ceramics have and also adds an extra dimension to the object. Other techniques include washing, dry brushing, and stippling. For more info on painting techniques, check out this blog.
  • Let each coat of paint dry, especially the first coat! Layering the colors is much easier if each layer is dry. This prevents two or more paint colors from mixing and allows you to keep the texture of the object exactly how you want it. Plus, it makes for a less messy painting experience…or, at least, it helps.
  • Do not be afraid to mix paint to get the exact color you need. Sometimes the exact color we need to use does not come straight from the tube. For example, to get the perfect brown, I sometimes have to mix lighter shades in with darker shades, or add red, yellow, black, or white to get the tones right. Do not be afraid to experiment!
  • Use one color at a time. What I mean is, focus on one or two colors on the object and paint those all at once. This makes it easier for you to maintain the same colors throughout the object, especially if you had to make a custom color. This way, you don’t need to remember the exact ratios and colors.
  • Always use a clean brush whether it’s brand new or just washed. Accidentally mixing your last color with your newest color can mess up your work.
  • If you are painting ceramics that have a glaze over the artifact, I suggest using glue as the final step to create a shiny surface that mimics the glaze.
  • Do not be afraid to mess up! The best thing about painting is you can always paint over anything you do not like. Painting is very forgiving because no matter how many times you feel you may have messed up, you can always re-paint!
ramie-ceramics
These are some ceramics from sites along Garcon Point in Pensacola. The artifacts on the right are real and the ones on the left are painted. These were painted by graduate students Jane Holmstrom, Katy Patterson, and myself.

Depending on the artifact, painting can take a few hours. Overall, 3D scanning and printing can be a tedious process that is only lengthened (but greatly enhanced!) by painting. Scanning an artifact can take anywhere from 30 minutes to an hour and a half. Printing is the longest step that could take up to several hours, depending on the size and complexity of the model. The olive jar neck sherd, that I will walk you through next month, took approximately an hour to scan, an hour to print, and 30 minutes to paint. While these processes can be time consuming, they greatly enhance the public’s experience with archaeology!

I hope this painting tutorial helped give you some tips, tricks, and ideas for painting plastic artifacts in your very own lab! I would love to know what you think, so please feel free to leave any questions or comments!

 


Mariana Zechini is a graduate student at the University of West Florida. She received her B.S. in Anthropology at Virginia Commonwealth University in 2014 and has four years of experience in 3D scanning archaeological materials. Her thesis focuses on analyzing stable isotopes from human remains from a medieval cemetery site in Berlin, Germany.

The Basic PhotoScan Process – Step 7

Photogrammetry has incredible potential in archaeological research and education. However, despite Agisoft PhotoScan’s relatively simple initial workflow, things get complicated pretty quickly. Those of us using the program tend to learn by solving problems as they occur, but this is a very piecemeal, time-consuming, and often frustrating process. Currently, anyone getting started with the program must either go through the same thing, or find someone to offer guidance.

In this series I will assemble all the separate tips that I have learned or found into a step-by-step guide on the basic process (posted weekly). I do not consider myself an expert in PhotoScan. If you are familiar with the program and have any corrections or additions, please let me know.Each week, the previous step will be edited to include any comments and placed under the “Resources” menu to serve as a guide for beginners.

The previous steps can be found here.

Step 7: Building the Texture

Time for the final step in this series, texturing your model! If you only plan to use your model for 3D printing, then this part is unnecessary. However, one of the strengths of photogrammetry is that the photos themselves can be used to make your model look like the original object.

Changing the High Contrast Images

First of all, if you used edited, high contrast images in Step 2 we will want to change them back so the final texture is accurate (otherwise skip this part and move on to “Texturing” section). To do this:

  1. Right click one of your images in PhotoScan and select “Change Path…” on the menu that appears.
  2. A window will pop up, navigate to your original, unedited photos.
  3. Only the image that you right clicked on will show up, that is fine. Select it and click “Open.”
  4. A window titled “Relocate Photos” will appear. Select “Entire workspace” and hit “OK.”

You now have a model built with the high contrast images and the unedited images in place for your texture.

Texturing

texture-windowTo add a texture to your model, go to your “Workflow” menu one last time and select “Build Texture…” A window will pop up with some more options.

  • “Mapping mode” should be on “Generic” most of the time. “Adaptive Orthophoto” might be good if you are working with aerials or a relatively flat subject.
  • “Blending mode” should be on “Mosaic (default)” as this will chose the most appropriate photo for the texture.
  • “Texture size/count” will depend on the detail you want and your system requirements. The first box indicates the dimensions of the texture image. Larger numbers will give you finer detail (so long as your photos are in a high enough resolution) but can be very taxing on your computer’s RAM if they are too big. The second box will help you get around that by producing multiple files instead of just one large one.

Under the “Advanced” tab you will find:

  • An “Enable color correction” checkbox which is supposed to even out lighting from photo to photo. I leave this unchecked.
  • An “Enable hole filling” checkbox which will attempt to add a texture to places that were not covered by the photos. Depending on the object, how big the hole is, and how concerned you are with accuracy, the program’s attempt to fill these spaces in is usually obvious, but better than nothing.

Click “Okay” when you are satisfied. When PhotoScan is done processing you have a finished 3D model! You can now upload it directly to Sketchfab under the “File” menu or export it (obj or stl is recommended) to print or work with it in Blender or Meshlab.

 


That concludes the Basic PhotoScan Process series but there is plenty more to talk about. This final entry will be added to the permanent page next week. If you have a tutorial series you would like to see or do, just let us know!

The Basic PhotoScan Process – Step 6

Photogrammetry has incredible potential in archaeological research and education. However, despite Agisoft PhotoScan’s relatively simple initial workflow, things get complicated pretty quickly. Those of us using the program tend to learn by solving problems as they occur, but this is a very piecemeal, time-consuming, and often frustrating process. Currently, anyone getting started with the program must either go through the same thing, or find someone to offer guidance.

In this series I will assemble all the separate tips that I have learned or found into a step-by-step guide on the basic process (posted weekly). I do not consider myself an expert in PhotoScan. If you are familiar with the program and have any corrections or additions, please let me know.Each week, the previous step will be edited to include any comments and placed under the “Resources” menu to serve as a guide for beginners.

The previous steps can be found here.

Step 6: Building the Mesh

You have created your dense point cloud and it is time to turn all of those points into a “solid” object. Before proceeding though, check your dense cloud for any errors and remove them the same way you did with the sparse cloud. I always have some cleaning up to do, but not nearly as much since I started doing the “Gradual Selection” process in Step 4.


select-points-by-color-windowJeremiah Stager
points out that you can further clean up the dense cloud by going to Tools> Dense Cloud> Select Points by Color. He recommends starting with white or black and increasing the tolerance to remove points that are errors in the model.

Now, go to your “Workflow” drop-down menu again and select “Build Mesh…” and the relevant window will pop up with new options.

  • mesh-building-window“Surface Type” should be left at “Arbitrary” unless you are modeling from aerial photography.
  • “Source Data” should be your dense cloud. If the menu says “Sparse cloud” switch it.
  • “Face Count” puts a limit on how many triangles PhotoScan will apply. When we turn these points into a solid object, the resulting model is made up of lots of little triangles. Each triangle is a face. When making a model to share on Sketchfab 500,000 faces is a good upper limit. I have had good luck with up to 1 million faces, though this is close to what my computer can comfortably handle (once I apply a texture in Step 7). If you put “0” in this box you are placing no limit on the number of faces. Be careful with this, I have accidently created models with over 22 million faces this way. This made my computer cry.

Under the “Advanced” tab:

  • “Interpolation” describes how much the program automatically fills in holes. “Enabled (default)” is the middle ground where small holes are filled in. If you need perfect accuracy and do not mind holes you can select “Disabled” otherwise “Extrapolated” makes sure there are no holes left.
  • “Point Classes” I think are related to more aerial photographs. Here is a tutorial on creating them if you need it, otherwise ignore this option.

Click “OK” when you are satisfied. The progress window will pop up again. This may take up to an hour.